676 research outputs found

    Geologic Setting and Activity of Faults in the San Fernando Area, California

    Get PDF
    The faulting associated with the San Fernando earthquake of February 9, 1971, occurred in the Transverse Ranges structural province, a region noted for its strong and relatively young tectonic deformation. This is, however, the first example of historic surface faulting within the interior of that province

    Heat exchange mediated by a quantum system

    Full text link
    We consider heat transfer between two thermal reservoirs mediated by a quantum system using the generalized quantum Langevin equation. The thermal reservoirs are treated as ensembles of oscillators within the framework of the Drude-Ullersma model. General expressions for the heat current and thermal conductance are obtained for arbitrary coupling strength between the reservoirs and the mediator and for different temperature regimes. As an application of these results we discuss the origin of Fourier's law in a chain of large, but finite subsystems coupled to each other by the quantum mediators. We also address a question of anomalously large heat current between the STM tip and substrate found in a recent experiment. The question of minimum thermal conductivity is revisited in the framework of scaling theory as a potential application of the developed approach.Comment: 16 pages, 6 figure

    Geologic Setting and Activity of Faults in the San Fernando Area, California

    Get PDF
    The faulting associated with the San Fernando earthquake of February 9, 1971, occurred in the Transverse Ranges structural province, a region noted for its strong and relatively young tectonic deformation. This is, however, the first example of historic surface faulting within the interior of that province

    Fast by Nature - How Stress Patterns Define Human Experience and Performance in Dexterous Tasks

    Get PDF
    In the present study we quantify stress by measuring transient perspiratory responses on the perinasal area through thermal imaging. These responses prove to be sympathetically driven and hence, a likely indicator of stress processes in the brain. Armed with the unobtrusive measurement methodology we developed, we were able to monitor stress responses in the context of surgical training, the quintessence of human dexterity. We show that in dexterous tasking under critical conditions, novices attempt to perform a task's step equally fast with experienced individuals. We further show that while fast behavior in experienced individuals is afforded by skill, fast behavior in novices is likely instigated by high stress levels, at the expense of accuracy. Humans avoid adjusting speed to skill and rather grow their skill to a predetermined speed level, likely defined by neurophysiological latency

    Egalitarian despots: hierarchy steepness, reciprocity and the grooming-trade model in wild chimpanzees (Pan troglodytes)

    Get PDF
    Biological-markets theory models the action of natural selection as a marketplace in which animals are viewed as traders with commodities to offer and exchange. Studies of female Old World monkeys have suggested that grooming might be employed as a commodity to be reciprocated or traded for alternative services, yet previous tests of this grooming-trade model in wild adult male chimpanzees (Pan troglodytes) have yielded mixed results. Here we provide the strongest test of the model to date for male chimpanzees: we use data drawn from two social groups (communities) of chimpanzees from different populations, and give explicit consideration to variation in dominance hierarchy steepness as such variation results in differing conditions for biological markets. First, analysis of data from published accounts of other chimpanzee communities, together with our own data, showed that hierarchy steepness varied considerably within and across communities and that the number of adult males in a community aged 20-30 years predicted hierarchy steepness. The two communities in which we tested predictions of the grooming-trade model lay at opposite extremes of this distribution. Second, in accord with the grooming-trade model, we found evidence that male chimpanzees trade grooming for agonistic support where hierarchies are steep (despotic) and consequent effective support is a rank-related commodity, but not where hierarchies are shallow (egalitarian). However, we also found that grooming was reciprocated regardless of hierarchy steepness. Our findings also hint at the possibility of agonistic competition, or at least exclusion, in relation to grooming opportunities compromising the free market envisioned by Biological Markets theory. Our results build on previous findings across chimpanzee communities to emphasise the importance of reciprocal grooming exchanges among adult male chimpanzees, which can be understood in a biological markets framework if grooming by or with particular individuals is a valuable commodity

    The Relationships among Trait Anxiety, State Anxiety and the Goal Performance of Penalty Shoot-Out by University Soccer Players

    Get PDF
    The present study examined how the level of trait anxiety, which is a personality characteristic, influences state anxiety and penalty shoot-out performance under pressure by instruction. The high and low trait anxiety groups were selected by using Spielberger's Trait Anxiety Scale, with trait anxiety scores, and control and pressure conditions manipulated by instructions. The participants were two groups of eight university male soccer players. They individually performed 20 shots from the penalty shoot-out point, aiming at the top right and top left corner areas in the soccer goal. Each condition had 10 trials in a within-subject design. The dependent measures comprised the number of successful goals and the state anxiety scores under each instructional condition. The result showed a significant main effect of instruction. State anxiety scores increased more and the number of successful goals decreased more in high trait anxiety groups than in low trait anxiety groups under pressure instructional condition. These findings suggest that players with higher trait anxiety scores tend to experience increased state anxiety under a pressure-laden condition, and higher state anxiety interferes with goal performance

    In photosynthesis, oxygen comes from water: from a 1787 book for women by Monsieur De Fourcroy

    Get PDF
    Abstract It is now well established that the source of oxygen in photosynthesis is water. The earliest suggestion previously known to us had come from René Bernard Wurmser (1930). Here, we highlight an earlier report by Monsieur De Fourcroy (1787), who had already discussed the broad outlines of such a hypothesis in a book on Chemistry written for women. We present here a free translation of a passage from this book, with the original text in French as an Appendix

    Hakim Revisited: Preference, Choice and the Postfeminist Gender Regime

    Get PDF
    Abstract We revisit Hakim’s influential preference theory to demonstrate how it is both reflective of postfeminism and generative of its values and practices. We differentiate between two interpretations of postfeminism – first a surface level “successful but obsolete” version articulated by Hakim and a second, multi-layered account of postfeminism as a discursive formation connected to a set of discourses around gender, feminism and femininity. Drawing on this latter version we make visible the embeddedness of postfeminism in preference theory highlighting its connection to the creation of a new postfeminist subjectivity based on an agentic and ‘choosing’ femininity. We show how a consideration of preference theory in terms of the emergence and constitution of “the female chooser”, opens up aspects of Hakim’s thesis which to date have been overlooked. In addition, our postfeminist reading of preference theory draws out aspects of Hakim’s account which she herself understated. Specifically, within a contemporary context where equivalent priority is afforded to wage-work and care work, it is Hakim’s ‘adaptive’ woman who exemplifies the new postfeminist subject required to perform well simultaneously in both the work and domestic domains
    corecore