23,602 research outputs found

    Definition of the Subfamily Hedobiinae Based on Larval Characteristics (Coleoptera: Anobiidae)

    Get PDF
    Recently, Espanol (1968, 1970) redefined the subfamily Hedobiinae and, using the anatomy of adults, presented a key to separate the eight genera which form it. He also introduced some notable modifications, among them the inclusion of Ptilineurus and Clada in the subfamily and the elevation of Ptinomorphus Mulsant and Rey to generic rank. The latter genus includes, among others, the species P. imperialis Linnaeus and regalis Duftschmid, from Europe and P. granosus LeConte and angularus Fall from the United States of America

    Adaptation to criticality through organizational invariance in embodied agents

    Get PDF
    Many biological and cognitive systems do not operate deep within one or other regime of activity. Instead, they are poised at critical points located at phase transitions in their parameter space. The pervasiveness of criticality suggests that there may be general principles inducing this behaviour, yet there is no well-founded theory for understanding how criticality is generated at a wide span of levels and contexts. In order to explore how criticality might emerge from general adaptive mechanisms, we propose a simple learning rule that maintains an internal organizational structure from a specific family of systems at criticality. We implement the mechanism in artificial embodied agents controlled by a neural network maintaining a correlation structure randomly sampled from an Ising model at critical temperature. Agents are evaluated in two classical reinforcement learning scenarios: the Mountain Car and the Acrobot double pendulum. In both cases the neural controller appears to reach a point of criticality, which coincides with a transition point between two regimes of the agent's behaviour. These results suggest that adaptation to criticality could be used as a general adaptive mechanism in some circumstances, providing an alternative explanation for the pervasive presence of criticality in biological and cognitive systems.Comment: arXiv admin note: substantial text overlap with arXiv:1704.0525

    Masses of the Goldstone modes in the CFL phase of QCD at finite density

    Get PDF
    We construct the U_L(3) x U_R(3) effective lagrangian which encodes the dynamics of the low energy pseudoscalar excitations in the Color-Flavor-Locking superconducting phase of QCD at finite quark density. We include the effects of instanton-induced interactions and study the mass pattern of the pseudoscalar mesons. A tentative comparison with the analytical estimate for the gap suggests that some of these low energy momentum modes are not stable for moderate values of the quark chemical potential.Comment: 15 pages, 5 figures; Discussion of quark mass effects at very large densities amended, references adde

    Dissipative processes in superfluid quark matter

    Full text link
    We present some results about dissipative processes in fermionic superfluids that are relevant for compact stars. At sufficiently low temperatures the transport properties of a superfluid are dominated by phonons. We report the values of the bulk viscosity, shear viscosity and thermal conductivity of phonons in quark matter at extremely high density and low temperature. Then, we present a new dissipative mechanism that can operate in compact stars and that is named "rocket term". The effect of this dissipative mechanism on superfluid r-mode oscillations is sketched.Comment: 6 pages, 1 figure. Prepared for QCD@work 2010 - International Workshop on QCD - Theory and Experiment, 20-23 June 2010, Martina Franca - Valle d'Itria - Ital

    Promoting Hope, Healing, and Wellness: Catholic Interventions in Behavioral Health Care

    Get PDF
    In this chapter, we will outline, highlight, and review some of the Catholic traditions and pastoral tools that can be integrated into any professional clinical practice in behavioral health care. We will focus our attention on six tools in particular that are particularly popular and unique within the Catholic faith tradition. We will also offer brief case illustrations to provide examples of how these Catholic tools can be effectively integrated into professional clinical practice

    SURVIVAL OF THE SMALL FIRM AND THE ENTREPRENEUR UNDER DEMAND AND EFFICIENCY UNCERTAINTY

    Get PDF
    The objective of this paper is to offer an answer to the question : why do some entrepreneurs wish to own another firm in the future after having closed an unsuccessful one? We first show this question is relevant because making use of a sample of entrepreneurs in the UK who have experienced a business closure, we show that 45% of them have the desire to own another firm in the future, despite having an unsuccessful experience in small firm ownership. To tackle our question we develop a model where the profits of the small firm depend on two firm-specific parameters : the effciency parameter, which represents the skills of the entrepreneur to manage and cope efficiently with the everyday tasks of the small firm, and the demand parameter, which denotes the success of the firm’s product to attract demand or capture a market niche. It is found that our model answers our initial question by revealing the existence of a mechanism of entrepreneurial self-selection. Under such mechanism, skilful entrepreneurs are the only ones who wish to own another firm in the future, regardless of the degree of success in their previous venture, whereas unskilful entrepreneurs prefer to go to wage work. We show this mechanism accounts not only for the empirical evidence relevant to our initial question, but also for the rest of cases of entrepreneurs’ attitudes after experiencing a business closureSmall Firm ; Entrepreneur ; Survival ; Entrepreneurial Skills
    • …
    corecore