3,947 research outputs found

    Towards a Lightweight Approach for Modding Serious Educational Games: Assisting Novice Designers

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    Serious educational games (SEGs) are a growing segment of the education community’s pedagogical toolbox. Effectively creating such games remains challenging, as teachers and industry trainers are content experts; typically they are not game designers with the theoretical knowledge and practical experience needed to create a quality SEG. Here, a lightweight approach to interactively explore and modify existing SEGs is introduced, a toll that can be broadly adopted by educators for pedagogically sound SEGs. Novice game designers can rapidly explore the educational and traditional elements of a game, with a stress on tracking the SEG learning objectives, as well as allowing for reviewing and altering a variety of graphic and audio game elements

    Modeling Life as Cognitive Info-Computation

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    This article presents a naturalist approach to cognition understood as a network of info-computational, autopoietic processes in living systems. It provides a conceptual framework for the unified view of cognition as evolved from the simplest to the most complex organisms, based on new empirical and theoretical results. It addresses three fundamental questions: what cognition is, how cognition works and what cognition does at different levels of complexity of living organisms. By explicating the info-computational character of cognition, its evolution, agent-dependency and generative mechanisms we can better understand its life-sustaining and life-propagating role. The info-computational approach contributes to rethinking cognition as a process of natural computation in living beings that can be applied for cognitive computation in artificial systems.Comment: Manuscript submitted to Computability in Europe CiE 201

    Instrument-assisted Soft Tissue Mobilization: Effects on the Properties of Human Plantar Flexors

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    The effect of instrument-assisted soft tissue mobilization (ISTM) on passive properties and inflammation in human skeletal muscle has not been evaluated. Passive properties of muscle, inflammatory myokines and subjective reporting of functional ability were used to identify the effects of ISTM on the plantar flexors. 11 healthy men were measured for passive musculotendinous stiffness (MTS), passive range of motion (PROM), passive resistive torque (PASTQ) and maximum voluntary contraction peak torque (MVCPT) for plantar flexor muscles of the lower leg. Interleukin-6 (IL-6) and tumor necrosis factor-alpha (TNF-α) were measured from muscle biopsies from the gastrocnemius, and subjective measurements of functional ability were taken using the perception of functional ability questionnaire (PFAQ). MTS, PROM, PRT and MVCPT were measured in the treatment leg (TL) and control leg (CL) before, immediately after, 24 h, 48 h and 72 h following IASTM. Biopsies for IL-6 and TNF-α and PFAQ responses were collected before as well as 24 h, 48 h and 72 h after IASTM. There were no significant differences in MTS, PROM, PASTQ, MVCPT, IL-6 and TNF-α between the TL or CL. A significant decrease in the perception of function and a significant increase in pain for the TL were found following IASTM

    Effect of volcanic dykes on coastal groundwater flow and saltwater intrusion : a field-scale multiphysics approach and parameter evaluation

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    Acknowledgments This research was primarily based on research grant‐aided by the Irish Department of Communications, Energy and Natural Resources under the National Geoscience Programme 2007–2013. It also benefited from complementary funding from the Scottish Alliance for Geoscience, Environment and Society (SAGES). We acknowledge the contribution in data acquisition of the MSc students in Environmental Engineering at Queen's University Belfast, the landowner for access to the inland fields and the Department of Geography, Archaeology and Paleoecology at QUB for provision of the tidal model of Belfast Lough. The data used are listed in the references, tables, and figures and are available from the corresponding author upon demand. We acknowledge the constructive comments by the Associate Editor and three reviewers, which helped in improving the final manuscript.Peer reviewedPublisher PD

    Export of Asian pollution during two cold front episodes of the TRACE-P experiment

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    Two cold front episodes were sampled during the two flights out of Yokota, Japan, during the Transport and Chemical Evolution Over the Pacific (TRACE-P) experiment during March 2001. The data from these two flights are examined using a mesoscale three-dimensional model. We show how these cyclonic systems have impacted the export of pollution out of the Asian continent. We contrast the relative role of convection and ascent in the warm conveyor belts associated with the cyclone during these two episodes. Although the necessary meteorological conditions for an efficient export of pollution are met during flight 13 (i.e., the occurrences of the warm conveyor belt near the source regions), no significant pollution is simulated in the mid-Pacific in the lower and middle troposphere. The efficient ventilation of the WCB by convection near the coast, the advection by the anticyclonical flow above 700 hPa, and the downward motion associated with the Pacific high in the remote ocean significantly prevent any long-range transport of undiluted pollution in the WCB. During flight 15 the conveyor belts have already moved to the remote ocean. The polluted plume is split by the rising air in the warm conveyor belt which transports CO-poor air northward and by the oceanic convection which transports clean air masses upward. These mechanisms lead to the dilution of Asian pollution in WCB en route to North America and add to the episodic nature of the Asian outflow by fragmenting the pollution plume

    Interspecific hybridization explains rapid gorget colour divergence in Heliodoxa hummingbirds (Aves: Trochilidae)

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    Hybridization is a known source of morphological, functional and communicative signal novelty in many organisms. Although diverse mechanisms of established novel ornamentation have been identified in natural populations, we lack an understanding of hybridization effects across levels of biological scales and upon phylogenies. Hummingbirds display diverse structural colours resulting from coherent light scattering by feather nanostructures. Given the complex relationship between feather nanostructures and the colours they produce, intermediate coloration does not necessarily imply intermediate nanostructures. Here, we characterize nanostructural, ecological and genetic inputs in a distinctive Heliodoxa hummingbird from the foothills of eastern Peru. Genetically, this individual is closely allied with Heliodoxa branickii and Heliodoxa gularis, but it is not identical to either when nuclear data are assessed. Elevated interspecific heterozygosity further suggests it is a hybrid backcross to H. branickii. Electron microscopy and spectrophotometry of this unique individual reveal key nanostructural differences underlying its distinct gorget colour, confirmed by optical modelling. Phylogenetic comparative analysis suggests that the observed gorget coloration divergence from both parentals to this individual would take 6.6–10 My to evolve at the current rate within a single hummingbird lineage. These results emphasize the mosaic nature of hybridization and suggest that hybridization may contribute to the structural colour diversity found across hummingbirds

    Robust optical delay lines via topological protection

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    Phenomena associated with topological properties of physical systems are naturally robust against perturbations. This robustness is exemplified by quantized conductance and edge state transport in the quantum Hall and quantum spin Hall effects. Here we show how exploiting topological properties of optical systems can be used to implement robust photonic devices. We demonstrate how quantum spin Hall Hamiltonians can be created with linear optical elements using a network of coupled resonator optical waveguides (CROW) in two dimensions. We find that key features of quantum Hall systems, including the characteristic Hofstadter butterfly and robust edge state transport, can be obtained in such systems. As a specific application, we show that the topological protection can be used to dramatically improve the performance of optical delay lines and to overcome limitations related to disorder in photonic technologies.Comment: 9 pages, 5 figures + 12 pages of supplementary informatio

    The Lick AGN Monitoring Project 2011: Dynamical Modeling of the Broad-Line Region

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    We present models of the HÎČ\beta-emitting broad-line region (BLR) in seven Seyfert 1 galaxies from the Lick AGN (Active Galactic Nucleus) Monitoring Project 2011 sample, drawing inferences on the BLR structure and dynamics as well as the mass of the central supermassive black hole. We find that the BLR is generally a thick disk, viewed close to face-on, with preferential emission back toward the ionizing source. The dynamics in our sample range from near-circular elliptical orbits to inflowing or outflowing trajectories. We measure black hole masses of log⁥10(MBH/M⊙)=6.48−0.18+0.21\log_{10}(M_{\rm BH}/M_\odot) = 6.48^{+0.21}_{-0.18} for PG 1310−-108, 7.50−0.18+0.257.50^{+0.25}_{-0.18} for Mrk 50, 7.46−0.21+0.157.46^{+0.15}_{-0.21} for Mrk 141, 7.58−0.08+0.087.58^{+0.08}_{-0.08} for Mrk 279, 7.11−0.17+0.207.11^{+0.20}_{-0.17} for Mrk 1511, 6.65−0.15+0.276.65^{+0.27}_{-0.15} for NGC 4593, and 6.94−0.14+0.146.94^{+0.14}_{-0.14} for Zw 229−-015. We use these black hole mass measurements along with cross-correlation time lags and line widths to recover the scale factor ff used in traditional reverberation mapping measurements. Combining our results with other studies that use this modeling technique, bringing our sample size to 16, we calculate a scale factor that can be used for measuring black hole masses in other reverberation mapping campaigns. When using the root-mean-square (rms) spectrum and using the line dispersion to measure the line width, we find log⁥10(frms,σ)pred=0.57±0.19\log_{10}(f_{{\rm rms},\sigma})_{\rm pred} = 0.57 \pm 0.19. Finally, we search for correlations between ff and other AGN and BLR parameters and find marginal evidence that ff is correlated with MBHM_{\rm BH} and the BLR inclination angle, but no significant evidence of a correlation with the AGN luminosity or Eddington ratio.Comment: 26 pages, 14 figures. Accepted for publication in Ap

    Acknowledging uncertainty in evolutionary reconstructions of ecological niches

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    Reconstructing ecological niche evolution can provide insight into the biogeography and diversification of evolving lineages. However, comparative phylogenetic methods may infer the history of ecological niche evolution inaccurately because (a) species' niches are often poorly characterized; and (b) phylogenetic comparative methods rely on niche summary statistics rather than full estimates of species' environmental tolerances. Here, we propose a new framework for coding ecological niches and reconstructing their evolution that explicitly acknowledges and incorporates the uncertainty introduced by incomplete niche characterization. Then, we modify existing ancestral state inference methods to leverage full estimates of environmental tolerances. We provide a worked empirical example of our method, investigating ecological niche evolution in the New World orioles (Aves: Passeriformes: Icterus spp.). Temperature and precipitation tolerances were generally broad and conserved among orioles, with niche reduction and specialization limited to a few terminal branches. Tools for performing these reconstructions are available in a new R package called nichevol

    Acknowledging uncertainty in evolutionary reconstructions of ecological niches

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    Reconstructing ecological niche evolution can provide insight into the biogeography and diversification of evolving lineages. However, comparative phylogenetic methods may infer the history of ecological niche evolution inaccurately because (a) species' niches are often poorly characterized; and (b) phylogenetic comparative methods rely on niche summary statistics rather than full estimates of species' environmental tolerances. Here, we propose a new framework for coding ecological niches and reconstructing their evolution that explicitly acknowledges and incorporates the uncertainty introduced by incomplete niche characterization. Then, we modify existing ancestral state inference methods to leverage full estimates of environmental tolerances. We provide a worked empirical example of our method, investigating ecological niche evolution in the New World orioles (Aves: Passeriformes: Icterus spp.). Temperature and precipitation tolerances were generally broad and conserved among orioles, with niche reduction and specialization limited to a few terminal branches. Tools for performing these reconstructions are available in a new R package called nichevol
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