4,157 research outputs found

    How artists fit into research processes

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    © 2010 ISAST. The study collects, compares and synthesises existing knowledge from specific sources about artists and creative designers working within research processes. The emphasis is on collaboration, evaluation and reflective practice

    Weak rappers rock more: Hermit crabs assess their own agonistic behaviour.

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    Fighting animals use a variety of information sources to make strategic decisions. A neglected potential source of information is an individual’s own performance during a fight. Surprisingly, this possibility has yet to be incorporated into the large body of theory concerning the evolution of aggressive behaviour. Here we test for the possibility that attacking hermit crabs monitor their own fight performance by experimentally dampening the impact of their shell rapping behaviour. Attackers with dampened raps did not show a reduction in the number of raps used. In contrast, they showed an increased frequency of a less intense agonistic behaviour, shell rocking. This change in behaviour, in attackers that are forced to rap weakly, indicates that they assess their own agonistic behaviour

    Rotational States of Magnetic Molecules

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    We study a magnetic molecule that exhibits spin tunneling and is free to rotate about its anisotropy axis. Exact low-energy eigenstates of the molecule that are superpositions of spin and rotational states are obtained. We show that parameter α=2(ℏS)2/(IΔ)\alpha = 2(\hbar S)^2/(I\Delta) determines the ground state of the molecule. Here ℏS\hbar S is the spin, II is the moment of inertia, and Δ\Delta is the tunnel splitting. The magnetic moment of the molecule is zero at ααc\alpha \alpha_c. At α→∞\alpha \to \infty the spin of the molecule localizes in one of the directions along the anisotropy axis.Comment: 4 pages, 3 figure

    Renormalization of the tunnel splitting in a rotating nanomagnet

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    We study spin tunneling in a magnetic nanoparticle with biaxial anisotropy that is free to rotate about its anisotropy axis. Exact instanton of the coupled equations of motion is found that connects degenerate classical energy minima. We show that mechanical freedom of the particle renormalizes magnetic anisotropy and increases the tunnel splitting.Comment: 4 pages, 3 figure

    At what stage in the drinking process does drinking water affect attention and memory? Effects of mouth rinsing and mouth drying in adults

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    Drinking water is important for health and there is agreement that drinking water facilitates certain cognitive processes. However, the mechanism underlying the effect of drinking water on cognition is unknown. While attention performance is improved by even a very small drink, memory performance seems to require larger drinks for performance enhancement. This suggests that attention could be affected earlier in the drinking process than memory. We aimed to elucidate further the mechanism involved, by investigating the stage during the drinking process influencing performance on cognitive tasks. To this end, we compared mouth rinsing and mouth drying. Mouth rinsing was expected to result in improved attention performance and would suggest that the mechanism responsible is located in the mouth and occurs early in the drinking process, before swallowing. Eighty-seven adults participated in either a treatment (mouth rinsing or mouth drying) or control (no intervention) condition. They were assessed at baseline and 20 minutes later after intervention on measures of visual attention, short-term memory, subjective thirst and mood. Our results showed that mouth rinsing improved visual attention, but not short-term memory, mood or subjective thirst. Mouth drying did not affect performance. Our results support the hypothesis that different mechanisms underlie the effect of drinking water on different cognitive processes. They suggest that merely sipping water, as opposed to having a large drink, can improve attention

    Open vent volcanoes fuelled by depth-integrated magma degassing

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    Open-vent, persistently degassing volcanoes—such as Stromboli and Etna (Italy), Villarrica (Chile), Bagana and Manam (Papua New Guinea), Fuego and Pacaya (Guatemala) volcanoes—produce high gas fluxes and infrequent violent strombolian or ‘paroxysmal’ eruptions that erupt very little magma. Here we draw on examples of open-vent volcanic systems to highlight the principal characteristics of their degassing regimes and develop a generic model to explain open-vent degassing in both high and low viscosity magmas and across a range of tectonic settings. Importantly, gas fluxes from open-vent volcanoes are far higher than can be supplied by erupting magma and independent migration of exsolved volatiles is integral to the dynamics of such systems. The composition of volcanic gases emitted from open-vent volcanoes is consistent with its derivation from magma stored over a range of crustal depths that in general requires contributions from both magma decompression (magma ascent and/or convection) and iso- and polybaric second boiling processes. Prolonged crystallisation of water-rich basalts in crustal reservoirs produces a segregated exsolved hydrous volatile phase that may flux through overlying shallow magma reservoirs, modulating heat flux and generating overpressure in the shallow conduit. Small fraction water-rich melts generated in the lower and mid-crust may play an important role in advecting volatiles to subvolcanic reservoirs. Excessive gas fluxes at the surface are linked to extensive intrusive magmatic activity and endogenous crustal growth, aided in many cases by extensional tectonics in the crust, which may control the longevity and activity of open-vent volcanoes. There is emerging abundant geophysical evidence for the existence of a segregated exsolved magmatic volatile phase in magma storage regions in the crust. Here we provide a conceptual picture of gas-dominated volcanoes driven by magmatic intrusion and degassing throughout the crust

    Reconstructing a Simple Polytope from its Graph

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    Blind and Mani (1987) proved that the entire combinatorial structure (the vertex-facet incidences) of a simple convex polytope is determined by its abstract graph. Their proof is not constructive. Kalai (1988) found a short, elegant, and algorithmic proof of that result. However, his algorithm has always exponential running time. We show that the problem to reconstruct the vertex-facet incidences of a simple polytope P from its graph can be formulated as a combinatorial optimization problem that is strongly dual to the problem of finding an abstract objective function on P (i.e., a shelling order of the facets of the dual polytope of P). Thereby, we derive polynomial certificates for both the vertex-facet incidences as well as for the abstract objective functions in terms of the graph of P. The paper is a variation on joint work with Michael Joswig and Friederike Koerner (2001).Comment: 14 page

    Chandra X-ray Sources in the Collapsed-Core Globular Cluster M30 (NGC 7099)

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    We report the detection of six discrete, low-luminosity (Lx < 10^33 erg/s) X-ray sources, located within 12 arcsec of the center of the collapsed-core globular cluster M30 (NGC 7099), and a total of 13 sources within the half-mass radius, from a 50 ksec Chandra ACIS-S exposure. Three sources lie within the very small upper limit of 1.9 arcsec on the core radius. The brightest of the three core sources has a luminosity of Lx (0.5-6 keV) = 6x10^32 erg/s and a blackbody-like soft X-ray spectrum, which are both consistent with it being a quiescent low-mass X-ray binary (qLMXB). We have identified optical counterparts to four of the six central sources and a number of the outlying sources, using deep Hubble Space Telescope and ground-based imaging. While the two proposed counterparts that lie within the core may represent chance superpositions, the two identified central sources that lie outside of the core have X-ray and optical properties consistent with being CVs. Two additional sources outside of the core have possible active binary counterparts. We discuss the X-ray source population of M30 in light of its collapsed-core status.Comment: 18 pages, 13 figures (8 color), resubmitted to ApJ after incorporating referee comment

    It would be a Pleasure : Augmented Reality and Engagement in a Heritage Context

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    The interchangeability, confusion and conflict of what constitutes audience engagement has a long history, with much disagreement concerning boundaries and definitions. Dewey states that it is a mistake to see the artist as active and the audience as purely passive, and argues that “the active engagement of the audience is required to fully realise any work” (Dewey 1934). This predates the notions of “interactive” or “participatory” as understood today, but highlights the longstanding appreciation of the role the audience plays in the consumption of artworks. A sentiment echoed by Duchamp (1957) stating that “the spectator adds his contribution to the creative act”. The research project presented at EVA 2017 seeks to offer a model for engagement, that of pleasure, which explores methods to motivate active participation
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