1,121 research outputs found

    Antitrust Energy

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    Marking the centennial anniversary of Standard Oil Co. v. United States, we argue that much of the critique of antitrust enforcement and the skepticism about its social significance suffer from “Nirvana fallacy” — comparing existing and feasible policies to ideal normative policies, and concluding that the existing and feasible ones are inherently inefficient because of their imperfections. Antitrust law and policy have always been and will always be imperfect. However, they are alive and kicking. The antitrust discipline is vibrant, evolving, and global. This essay introduces a number of important innovations in scholarship related to Standard Oil and its modern applications and identifies shifts in antitrust that will keep the field energized for some time to come

    Antitrust Energy

    Get PDF
    Marking the centennial anniversary of Standard Oil Co. v. United States, we argue that much of the critique of antitrust enforcement and the skepticism about its social significance suffer from “Nirvana fallacy” — comparing existing and feasible policies to ideal normative policies, and concluding that the existing and feasible ones are inherently inefficient because of their imperfections. Antitrust law and policy have always been and will always be imperfect. However, they are alive and kicking. The antitrust discipline is vibrant, evolving, and global. This essay introduces a number of important innovations in scholarship related to Standard Oil and its modern applications and identifies shifts in antitrust that will keep the field energized for some time to come

    Limitations for change detection in multiple Gabor targets

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    We investigate the limitations on the ability to detect when a target has changed, using Gabor targets as simple quantifiable stimuli. Using a partial report technique to equalise response variables, we show that the log of the Weber fraction for detecting a spatial frequency change is proportional to the log of the number of targets, with a set-size effect that is greater than that reported for visual search. This is not a simple perceptual limitation, because pre-cueing a single target out of four restores performance to the level found when only one target is present. It is argued that the primary limitation on performance is the division of attention across multiple targets, rather than decay within visual memory. However in a simplified change detection experiment without cueing, where only one target of the set changed, not only was the set size effect still larger, but it was greater at 2000 msec ISI than at 250 msec ISI, indicating a possible memory component. The steepness of the set size effects obtained suggests that even moderate complexity of a stimulus in terms of number of component objects can overload attentional processes, suggesting a possible low-level mechanism for change blindness

    Phonon-phonon interactions and phonon damping in carbon nanotubes

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    We formulate and study the effective low-energy quantum theory of interacting long-wavelength acoustic phonons in carbon nanotubes within the framework of continuum elasticity theory. A general and analytical derivation of all three- and four-phonon processes is provided, and the relevant coupling constants are determined in terms of few elastic coefficients. Due to the low dimensionality and the parabolic dispersion, the finite-temperature density of noninteracting flexural phonons diverges, and a nonperturbative approach to their interactions is necessary. Within a mean-field description, we find that a dynamical gap opens. In practice, this gap is thermally smeared, but still has important consequences. Using our theory, we compute the decay rates of acoustic phonons due to phonon-phonon and electron-phonon interactions, implying upper bounds for their quality factor.Comment: 15 pages, 2 figures, published versio

    Quantum Thermoactivation of Nanoscale Magnets

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    The integral relaxation time describing the thermoactivated escape of a uniaxial quantum spin system interacting with a boson bath is calculated analytically in the whole temperature range. For temperatures T much less than the barrier height \Delta U, the level quantization near the top of the barrier and the strong frequency dependence of the one-boson transition probability can lead to the regularly spaced deep minima of the thermoactivation rate as a function of the magnetic field applied along the z axis.Comment: 4 pages, no figures, rejected from Phys. Rev. Let

    ‘Blindness to the obvious’?: Treatment experiences and feminist approaches to eating disorders

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    Eating disorders (EDs) are now often approached as biopsychosocial problems, but the social or cultural aspects of the equation are often marginalised in treatment - relegated to mere contributory or facilitating factors. In contrast, feminist and socio-cultural approaches are primarily concerned with the relationship between EDs and the social/ cultural construction of gender. Yet although such approaches emerged directly from the work of feminist therapists, the feminist scholarship has increasingly observed, critiqued and challenged the biomedical model from a scholarly distance. As such, this article draws upon data from 15 semi-structured interviews with women in the UK context who have experience of anorexia and/or bulimia in order to explore a series of interlocking themes concerning the relationship between gender identity and treatment. In engaging the women in debate about the feminist approaches (something which has been absent from previous feminist work), the article explores how gender featured in their own understandings of their problem, and the ways in which it was - or rather wasn’t - addressed in treatment. The article also explores the women’s evaluations of the feminist discourse, and their discussions of how it might be implemented within therapeutic and clinical contexts

    Extended longevity of DNA preservation in Levantine Paleolithic sediments, Sefunim Cave, Israel

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    Paleogenomic research can elucidate the evolutionary history of human and faunal populations. Although the Levant is a key land-bridge between Africa and Eurasia, thus far, relatively little ancient DNA data has been generated from this region, since DNA degrades faster in warm climates. As sediments can be a source of ancient DNA, we analyzed 33 sediment samples from different sedimentological contexts in the Paleolithic layers of Sefunim Cave (Israel). Four contained traces of ancient Cervidae and Hyaenidae mitochondrial DNA. Dating by optical luminescence and radiocarbon indicates that the DNA comes from layers between 30,000 and 70,000 years old, surpassing theoretical expectations regarding the longevity of DNA deposited in such a warm environment. Both identified taxa are present in the zooarchaeological record of the site but have since gone extinct from the region, and a geoarchaeological study suggests little movement of the sediments after their deposition, lending further support to our findings. We provide details on the local conditions in the cave, which we hypothesize were particularly conducive to the long-term preservation of DNA—information that will be pertinent for future endeavors aimed at recovering ancient DNA from the Levant and other similarly challenging contexts

    On the Nature of Memory and Rejuvenation in Glassy Systems

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    The memory effect in a single crystal spin glass (Cu0.92Mn0.08\mathrm{Cu}_{0.92}\mathrm{Mn}_{0.08}) has been measured using 1Hz1 \mathrm{Hz} ac susceptibility techniques over a reduced temperature range of 0.4−0.7 Tg0.4 - 0.7 \, T_g and a model of the memory effect has been developed. A double-waiting-time protocol is carried out where the spin glass is first allowed to age at a temperature below TgT_g, followed by a second aging at a lower temperature after it has fully rejuvenated. The model is based on calculating typical coincidences between the growth of correlated regions at the two temperatures. It accounts for the absolute magnitude of the memory effect as a function of both waiting times and temperatures. The data can be explained by the memory loss being a function of the relative change in the correlated volume at the first waiting temperature because of the growth in the correlations at the second waiting temperature.Comment: 11 pages, 6 figure

    Experimental evidence of a fractal dissipative regime in high-T_c superconductors

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    We report on our experimental evidence of a substantial geometrical ingredient characterizing the problem of incipient dissipation in high-T_c superconductors(HTS): high-resolution studies of differential resistance-current characteristics in absence of magnetic field enabled us to identify and quantify the fractal dissipative regime inside which the actual current-carrying medium is an object of fractal geometry. The discovery of a fractal regime proves the reality and consistency of critical-phenomena scenario as a model for dissipation in inhomogeneous and disordered HTS, gives the experimentally-based value of the relevant finite-size scaling exponent and offers some interesting new guidelines to the problem of pairing mechanisms in HTS.Comment: 5 pages, 3 figures, RevTex; Accepted for publication in Physical Review B; (figures enlarged
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