1,360 research outputs found

    Feeding live prey to zoo animals: response of zoo visitors in Switzerland

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    In summer 2007, with the help of a written questionnaire, the attitudes of more than 400 visitors to the zoological garden of Zurich, Switzerland, toward the idea of feeding live insects to lizards, live fish to otters, and live rabbits to tigers were investigated. The majority of Swiss zoo visitors agreed with the idea of feeding live prey (invertebrates and vertebrates) to zoo animals, both off- and on-exhibit, except in the case of feeding live rabbits to tigers on-exhibit. Women and frequent visitors of the zoo disagreed more often with the on-exhibit feeding of live rabbits to tigers. Study participants with a higher level of education were more likely to agree with the idea of feeding live invertebrates and vertebrates to zoo animals off-exhibit. In comparison to an earlier study undertaken in Scotland, zoo visitors in Switzerland were more often in favor of the live feeding of vertebrates. Feeding live prey can counter the loss of hunting skills of carnivores and improve the animals’ well-being. However, feeding enrichments have to strike a balance between optimal living conditions of animals and the quality of visitor experience. Our results show that such a balance can be found, especially when live feeding of mammals is carried out off-exhibit. A good interpretation of food enrichment might help zoos to win more support for the issue, and for re-introduction programs and conservation

    Articulatory Tradeoffs Reduce Acoustic Variability During American English /r/ Production

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    Acoustic and articulatory recordings reveal that speakers utilize systematic articulatory tradeoffs to maintain acoustic stability when producing the phoneme /r/. Distinct articulator configurations used to produce /r/ in various phonetic contexts show systematic tradeoffs between the cross-sectional areas of different vocal tract sections. Analysis of acoustic and articulatory variabilities reveals that these tradeoffs act to reduce acoustic variability, thus allowing large contextual variations in vocal tract shape; these contextual variations in turn apparently reduce the amount of articulatory movement required. These findings contrast with the widely held view that speaking involves a canonical vocal tract shape target for each phoneme.National Institute on Deafness and Other Communication Disorders (1R29-DC02852-02, 5R01-DC01925-04, 1R03-C2576-0l); National Science Foundation (IRI-9310518

    Neue Lerntechnologien für Umweltwissenschaften

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    Umweltwissenschaften/Ökologie sind durch ihren hohen Grad an Vernetzung, Inter- und Transdisziplinarität dazu prädestiniert, um umweltrelevantes Wissen mit "neuen Lerntechnologien" (E-Learning; internet-based learning; Multimedia-Unterricht) zu vermitteln. Dieser Beitrag stellt eine Auswahl von solchen Aktivitäten an den Universitäten Basel, Bern und Zürich sowie der ETH Zürich vor

    Exponential homogenization of linear second order elliptic PDEs with periodic coefficients

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    A problem of homogenization of a divergence-type second order uniformly elliptic operator is considered with arbitrary bounded rapidly oscillating periodic coefficients, either with periodic "outer" boundary conditions or in the whole space. It is proved that if the right-hand side is Gevrey regular (in particular, analytic), then by optimally truncating the full two-scale asymptotic expansion for the solution one obtains an approximation with an exponentially small error. The optimality of the exponential error bound is established for a one-dimensional example by proving the analogous lower bound

    Chaos in the Takens-Bogdanov bifurcation with O(2) symmetry

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    The Takens–Bogdanov bifurcation is a codimension two bifurcation that provides a key to the presence of complex dynamics in many systems of physical interest. When the system is translation invariant in one spatial dimension with no left-right preference the imposition of periodic boundary conditions leads to the Takens–Bogdanov bifurcation with O(2) symmetry. This bifurcation, analyzed by G. Dangelmayr and E. Knobloch, Phil. Trans. R. Soc. London A 322, 243 (1987), describes the interaction between steady states and traveling and standing waves in the nonlinear regime and predicts the presence of modulated traveling waves as well. The analysis reveals the presence of several global bifurcations near which the averaging method (used in the original analysis) fails. We show here, using a combination of numerical continuation and the construction of appropriate return maps, that near the global bifurcation that terminates the branch of modulated traveling waves, the normal form for the Takens–Bogdanov bifurcation admits cascades of period-doubling bifurcations as well as chaotic dynamics of Shil’nikov type. Thus chaos is present arbitrarily close to the codimension two point

    Green, circular, bio economy : A comparative analysis of sustainability avenues

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    Despite their evidently different assumptions and operationalization strategies, the concepts of Circular Economy, Green Economy and Bioeconomy are joined by the common ideal to reconcile economic, environmental and social goals. The three concepts are currently mainstreamed in academia and policy making as key sustainability avenues, but a comparative analysis of such concepts is missing. The aim of this article is thus to comprehensively analyse the diversity within and between such concepts. The results are drawn from a bibliometric review of almost two thousand scientific articles published within the last three decades, coupled with a conceptual analysis. We find that, for what concerns environmental sustainability, Green Economy acts as an 'umbrella' concept, including elements from Circular Economy and Bioeconomy concepts (e.g. eco-efficiency; renewables), as well as additional ideas, e.g. nature-based solutions. In particular, Circular Economy and Bioeconomy are resource-focused, whereas in principle Green Economy acknowledges the underpinning role of all ecological processes. Regarding the social dimension, Green Economy is more inclusive of some aspects at local level (e.g. eco-tourism, education), while there is an emerging discussion in Bioeconomy literature around local processes in terms of biosecurity and rural policies. When considering weak/strong sustainability visions, all concepts remain limited in questioning economic growth. By comparing the different sustainability strategies promoted by these concepts we do not advocate for their substitutability, but for their clarification and reciprocal integration. The findings are discussed in light of the concepts' synergies and limits, with the purpose to inform research and policy implementation. (C) 2017 The Authors. Published by Elsevier Ltd.Peer reviewe

    Long-distance optical-conveyor-belt transport of ultracold 133 Cs and 87 Rb atoms

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    We report on the transport of a thermal cloud of ultracold cesium and rubidium atoms over about 37 cm in under 25 ms using an optical conveyor belt formed by two counterpropagating beams with a controllable frequency difference that generate a movable optical lattice. By carefully selecting the waists and focus positions, we are able to use two static Gaussian beams for the transport, avoiding the need for a Bessel beam or variable-focus lenses. We characterize the transport efficiency for both species, including a comparison of different transport trajectories, gaining insight into the loss mechanisms and finding the minimum jerk trajectory to be optimum. Using the optimized parameters, we are able to transport up to 7×106 cesium or rubidium atoms with an efficiency up to 75%. To demonstrate the viability of our transport scheme for experiments employing quantum gas microscopy, we produce Bose-Einstein condensates of either species after transport and present measurements of the simultaneous transport of both species

    Billiard Systems in Three Dimensions: The Boundary Integral Equation and the Trace Formula

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    We derive semiclassical contributions of periodic orbits from a boundary integral equation for three-dimensional billiard systems. We use an iterative method that keeps track of the composition of the stability matrix and the Maslov index as an orbit is traversed. Results are given for isolated periodic orbits and rotationally invariant families of periodic orbits in axially symmetric billiard systems. A practical method for determining the stability matrix and the Maslov index is described.Comment: LaTeX, 19 page

    Trauma as counter-revolutionary colonisation: narratives from (post)revolutionary Egypt

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    We argue that multiple levels of trauma were present in Egypt before, during and after the 2011 revolution. Individual, social and political trauma constitute a triangle of traumatisation which was strategically employed by the Egyptian counter-revolutionary forces – primarily the army and the leadership of the Muslim Brotherhood – to maintain their political and economic power over and above the social, economic and political interests of others. Through the destruction of physical bodies, the fragmentation and polarisation of social relations and the violent closure of the newly emerged political public sphere, these actors actively repressed the potential for creative and revolutionary transformation. To better understand this multi-layered notion of trauma, we turn to Habermas’ ‘colonisation of the lifeworld’ thesis which offers a critical lens through which to examine the wider political and economic structures and context in which trauma occurred as well as its effects on the personal, social and political realms. In doing so, we develop a novel conception of trauma that acknowledges individual, social and political dimensions. We apply this conceptual framing to empirical narratives of trauma in Egypt’s pre- and post-revolutionary phases, thus both developing a non-Western application of Habermas’ framework and revealing ethnographic accounts of the revolution by activists in Cairo

    Efficient Analysis of High Dimensional Data in Tensor Formats

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    In this article we introduce new methods for the analysis of high dimensional data in tensor formats, where the underling data come from the stochastic elliptic boundary value problem. After discretisation of the deterministic operator as well as the presented random fields via KLE and PCE, the obtained high dimensional operator can be approximated via sums of elementary tensors. This tensors representation can be effectively used for computing different values of interest, such as maximum norm, level sets and cumulative distribution function. The basic concept of the data analysis in high dimensions is discussed on tensors represented in the canonical format, however the approach can be easily used in other tensor formats. As an intermediate step we describe efficient iterative algorithms for computing the characteristic and sign functions as well as pointwise inverse in the canonical tensor format. Since during majority of algebraic operations as well as during iteration steps the representation rank grows up, we use lower-rank approximation and inexact recursive iteration schemes
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