34 research outputs found

    Popovia johnrolandi n.sp., a new smaller agglutinated foraminifera from northern Venezuela: a biostratigraphic example of the second law of thermodynamics

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    We describe a previously unrecognised species of Popovia, here named Popovia johnrolandi n.sp. from the Miocene of Eastern Falcon state in Venezuela. The internal complexity of this new species increased through the Serravalian from Zone N10 to N14. This apparent trend towards increasing internal complexity reflects increasing entropy through time, and is here interpreted as an evolutionary adaptation to life within an oxygen minimum zone

    Some functional equations related to the characterizations of information measures and their stability

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    The main purpose of this paper is to investigate the stability problem of some functional equations that appear in the characterization problem of information measures.Comment: 36 pages. arXiv admin note: text overlap with arXiv:1307.0657, arXiv:1307.0631, arXiv:1307.0664, arXiv:1307.065

    QED3 theory of underdoped high temperature superconductors

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    Low-energy theory of d-wave quasiparticles coupled to fluctuating vortex loops that describes the loss of phase coherence in a two dimensional d-wave superconductor at T=0 is derived. The theory has the form of 2+1 dimensional quantum electrodynamics (QED3), and is proposed as an effective description of the T=0 superconductor-insulator transition in underdoped cuprates. The coupling constant ("charge") in this theory is proportional to the dual order parameter of the XY model, which is assumed to be describing the quantum fluctuations of the phase of the superconducting order parameter. The principal result is that the destruction of phase coherence in d-wave superconductors typically, and immediately, leads to antiferromagnetism. The transition can be understood in terms of the spontaneous breaking of an approximate "chiral" SU(2) symmetry, which may be discerned at low enough energies in the standard d-wave superconductor. The mechanism of the symmetry breaking is analogous to the dynamical mass generation in the QED3, with the "mass" here being proportional to staggered magnetization. Other insulating phases that break chiral symmetry include the translationally invariant "d+ip" and "d+is" insulators, and various one dimensional charge-density and spin-density waves. The theory offers an explanation for the rounded d-wave-like dispersion seen in ARPES experiments on Ca2CuO2Cl2 (F. Ronning et. al., Science 282, 2067 (1998)).Comment: Revtex, 20 pages, 5 figures; this is a much extended follow-up to the Phys. Rev. Lett. vol.88, 047006 (2002) (cond-mat/0110188); improved presentation, many additional explanations, comments, and references added, sec. IV rewritten. Final version, to appear in Phys. Rev.

    Self-harming behaviors in prison: a comparison of suicidal processes, self-injurious behaviors, and mixed events

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    Self-harming behaviors occurring in prison disproportionately consume resources and cause considerable disruption. To date, theoretical paradigms have explained self-injurious behaviors and suicidal processes either via a continuum or dichotomy of self-harm. This current study examines all documented acts of self-harm (n=1,158) occurring in South Carolina's 28 prisons over a 50 month period. We test and find support for a tripartite schema of self-harm; differentiated with regard to suicidal processes, self-injurious behaviors, and a 'mixed group' of self-harming behaviors. These groups of behaviors were distinct with regard to situational variables (i.e. body part targeted, injury severity) as well as institutional responses (i.e., medical treatment needed, employment of suicide protocols). Findings indicate that self-injurious behaviors are likely to result in physical injury and/or hospitalizations

    The evolution of language: a comparative review

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    For many years the evolution of language has been seen as a disreputable topic, mired in fanciful "just so stories" about language origins. However, in the last decade a new synthesis of modern linguistics, cognitive neuroscience and neo-Darwinian evolutionary theory has begun to make important contributions to our understanding of the biology and evolution of language. I review some of this recent progress, focusing on the value of the comparative method, which uses data from animal species to draw inferences about language evolution. Discussing speech first, I show how data concerning a wide variety of species, from monkeys to birds, can increase our understanding of the anatomical and neural mechanisms underlying human spoken language, and how bird and whale song provide insights into the ultimate evolutionary function of language. I discuss the ‘‘descended larynx’ ’ of humans, a peculiar adaptation for speech that has received much attention in the past, which despite earlier claims is not uniquely human. Then I will turn to the neural mechanisms underlying spoken language, pointing out the difficulties animals apparently experience in perceiving hierarchical structure in sounds, and stressing the importance of vocal imitation in the evolution of a spoken language. Turning to ultimate function, I suggest that communication among kin (especially between parents and offspring) played a crucial but neglected role in driving language evolution. Finally, I briefly discuss phylogeny, discussing hypotheses that offer plausible routes to human language from a non-linguistic chimp-like ancestor. I conclude that comparative data from living animals will be key to developing a richer, more interdisciplinary understanding of our most distinctively human trait: language

    The Physics of the B Factories

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