327 research outputs found

    Discretized best-response dynamics for the rock-paper-scissors game

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    Discretizing a differential equation may change the qualitative behaviour drastically, even if the stepsize is small. We illustrate this by looking at the discretization of a piecewise continuous differential equation that models a population of agents playing the Rock-Paper-Scissors game. The globally asymptotically stable equilibrium of the differential equation turns, after discretization, into a repeller surrounded by an annulus shaped attracting region. In this region, more and more periodic orbits emerge as the discretization step approaches zero

    Identification of factors associated with potential doping behavior in sports: A cross-sectional analysis in high-level competitive swimmers

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    Background: Doping behavior, including the misuse of performance-enhancing drugs, is currently a serious problem in sports, and the efficacy of preventive efforts directly depends on information regarding the associations among different precipitating factors (PF) and doping behavior. This study aimed to establish the PF of potential doping behavior (PDB) in competitive swimmers. Methods: The study included 301 swimmers from Slovenia (153 females, 16.4 \ub1 2.4 years), tested during the 2017 National Championship. Variables were collected by previously validated questionnaires, which included questions on sociodemographics, sports-related factors, consumption of dietary supplements, knowledge of doping, factors of hesitation, and doping-related factors (i.e., number of doping tests, opinion about the presence of doping in sport). The PDB (positive, neutral, or negative intention toward doping) was observed as a criterion, while other variables were included as predictors in multinomial regression analyses (with \u201cnegative\u201d as reference value), which additionally controlled for gender and age category (cadet-, junior-, and senior-level) as confounders. Results: The results confirmed higher susceptibility to doping in males (positive: odds ratio (OR): 2.77, 95% confidence interval (CI): 1.27\u20136.04), those swimmers who reported higher alcohol consumption (neutral: OR: 2.18, 95%CI: 1.06\u20134.16, positive: OR: 2.14, 95%CI: 1.05\u20134.37), and those regularly used dietary supplements (positive: OR: 3.62, 95%CI: 1.25\u201310.52). Competitive achievement in Olympic-(neutral: OR: 0.57, 95%CI: 0.41\u20130.81, positive: OR: 0.59, 95%CI: 0.39\u20130.88), and non-Olympic disciplines (positive: OR: 0.54, 95%CI: 0.35\u20130.83) was protective against PDB. Swimmers who were more concerned about the negative social consequences of doping behavior (i.e., condemnation by family and friends) were less likely to declare a positive intention toward the PDB (family condemnation: OR: 0.69, 95%CI: 0.56\u20130.86, friends\u2019 condemnation: OR: 0.65, 95%CI: 0.52\u20130.80). Conclusions: The results of the study provide more precise insight into the specific factors associated with PDB in swimming. The established precipitating factors should be incorporated into targeted anti-doping campaigns in this sport

    A framework for research on technology-enhanced special education

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    Based on results from the Technologies for Childrenwith Individual Needs Project and two case projects,we propose a new multidisciplinary framework forresearch between computer science, educationaltechnology, and special education. The frameworkpresents a way to conduct research that aims atdeveloping new methods for technology-enhancedspecial education and for developing adaptablesoftware and hardware tools for individual needs ineducational settings.Peer reviewe

    A game of common-pool resource management: Effects of communication, risky environment and worldviews

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    The ‘tragedy of the commons’ has been investigated for several decades. At its centre is the question whether a common resource will collapse under over-exploitation. The isolated analysis of one resource has many conceptual benefits, yet in reality resources and welfare are intertwined. In this paper, we investigate a situation where a resource which is exploited for profit has the additional feature of protecting against risk. Our main question is whether participants in an experimental game will prioritize such additional feature over maximizing profit and, if so, to what extent. Therefore, we designed a forest-harvesting game: Participants can harvest trees to generate income, and at the same time the forest serves as a protection against floods. Communication has been shown to play a vital role in managing commons. Our second aim is to test the importance of communication when the resource functions as a device of protecting against external risk. Lastly, we introduce a new perspective to the tragedy of the commons literature. Specifically, we investigate how the anthropologically motivated theory of risk perception (often called Cultural Theory) correlates with behaviour in our economic game. We believe that there is much potential in combining insights from these separate disciplines

    Integration of Human Factors in Surgery: Interdisciplinary Collaboration in Design, Development, and Evaluation of Surgical Technologies

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    Research in surgical intervention and technology development is increasingly interdisciplinary. Despite the great potential of working in this way, recent research suggests that interdisciplinary collaborations and competing stakeholder interests can be challenging to initiate and manage, with the result that knowledge and expertise from different fields are not always well integrated. The aim of this workshop is to bring together stakeholders from HCI, surgical science, and surgical practice and technology to investigate the potential of interdisciplinary collaboration, specifically identifying actionable strategies to coordinate and improve efforts towards designing, developing, evaluating, and iterating on the next generation of surgical solutions. The workshop will address current limitations in interdisciplinary collaboration, and identify opportunities for surgical technology stakeholders to make contributions across the entire development life cycle. In the longer term, the workshop will contribute towards the development of a pragmatic collaboration framework encompassing diverse research paradigms, compatible with surgical practice, and supportive of longitudinal evaluation

    Lightfastness assessment of Levantine rock art by means of microfading spectrometry

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    This is the peer reviewed version of the following article: del Hoyo-Meléndez JM, Carrión-Ruiz B, Riutort-Mayol G, Lerma JL. Lightfastness assessment of Levantine rock art by means of microfading spectrometry. Color Res Appl. 2019;44:547 555, which has been published in final form at https://doi.org/10.1002/col.22372. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Self-Archiving.[EN] The documentation of archeological sites requires the adoption of non-destructive techniques to safeguard the unique legacy coming from prehistoric periods. This article tackles the assessment of lightfastness properties on a rock art site to deter- mine the behavior of motif's color deterioration over time in Remi¿gia Cave, Castello¿n (Spain), which is considered part of a UNESCO World Heritage Site. The measurements were performed using a microfade testing device to analyze the spectral characteristics and the aging properties of the colorant system and various substrates on site. Two scenarios have been identified depending on whether the lightness (L*) parameter of the rocky substrate changes or not in relation with the painted motifs. If the substrate remains stable without any change, red motifs con- taining iron oxide pigments will become more visible. If the substrate becomes lighter, the pigments will experience similar changes. Therefore, the contrast between paintings and support will be considerably enhanced.The authors also would like to thank the Generalitat Valenciana for providing access to the site during the measurement campaigns. Fruitful comments from the Spanish archeologists Prof. Valentín Villaverde and Dra. Esther López-Montalvo are also gratefully acknowledged. The authors acknowledge the research project HAR2014-59873-R from the Spanish Ministerio de Economía y Competitividad for providing financial support.Del Hoyo-Meléndez, JM.; Carrión-Ruiz, B.; Riutort-Mayol, G.; Lerma, JL. (2019). Lightfastness assessment of Levantine rock art by means of microfading spectrometry. Color Research & Application. 44(4):547-555. https://doi.org/10.1002/col.22372S547555444Vileikis, O., Cesaro, G., Santana Quintero, M., van Balen, K., Paolini, A., & Vafadari, A. (2012). Documentation in World Heritage conservation. Journal of Cultural Heritage Management and Sustainable Development, 2(2), 130-152. doi:10.1108/20441261211273635Management Planning for Archaelogical Sites 2002 The Getty Conservation Institute Los Angeles G Palumbo Threats and challenges to the archaeological heritage in the Mediterranean 3 12ICOMOS. ICOMOS World Report 2000 on Monuments and Sites in Danger; 2000.https://www.icomos.org/risk/world_report/2000/risk2000.htm. Accessed October 25 2017.Giesen, M. J., Ung, A., Warke, P. A., Christgen, B., Mazel, A. D., & Graham, D. W. (2014). Condition assessment and preservation of open-air rock art panels during environmental change. Journal of Cultural Heritage, 15(1), 49-56. doi:10.1016/j.culher.2013.01.013Díez-Herrero, A., Gutiérrez-Pérez, I., Lario, J., Cañaveras, J. C., Benavente, D., Sánchez-Moral, S., & Alonso-Azcárate, J. (2009). Analysis of potential direct insolation as a degradation factor of cave paintings in Villar del Humo, Cuenca, Central Spain. Geoarchaeology, 24(4), 450-465. doi:10.1002/gea.20274López-Montalvo, E., Villaverde, V., Roldán, C., Murcia, S., & Badal, E. (2014). An approximation to the study of black pigments in Cova Remigia (Castellón, Spain). Technical and cultural assessments of the use of carbon-based black pigments in Spanish Levantine Rock Art. Journal of Archaeological Science, 52, 535-545. doi:10.1016/j.jas.2014.09.017Hernanz, A., Ruiz-López, J. F., Gavira-Vallejo, J. M., Martin, S., & Gavrilenko, E. (2010). Raman microscopy of prehistoric rock paintings from the Hoz de Vicente, Minglanilla, Cuenca, Spain. Journal of Raman Spectroscopy, 41(11), 1394-1399. doi:10.1002/jrs.2582Domingo, I., Villaverde, V., López-Montalvo, E., Lerma, J. L., & Cabrelles, M. (2013). Latest developments in rock art recording: towards an integral documentation of Levantine rock art sites combining 2D and 3D recording techniques. Journal of Archaeological Science, 40(4), 1879-1889. doi:10.1016/j.jas.2012.11.024Iturbe, A., Cachero, R., Cañal, D., & Martos, A. (2018). Digitalización de cuevas con arte paleolítico parietal de Bizkaia. Análisis científico y divulgación mediante nuevas técnicas de visualización. Virtual Archaeology Review, 9(18), 57. doi:10.4995/var.2018.7579Carrión-Ruiz, B., Blanco-Pons, S., & Lerma, J. L. (2016). DIGITAL IMAGE ANALYSIS OF THE VISIBLE REGION THROUGH SIMULATION OF ROCK ART PAINTINGS. Proceedings of the ARQUEOLÓGICA 2.0 8th International Congress on Archaeology, Computer Graphics, Cultural Heritage and Innovation. doi:10.4995/arqueologica8.2016.3560Fredlund, G., & Sundstrom, L. (2007). Digital infra-red photography for recording painted rock art. Antiquity, 81(313), 733-742. doi:10.1017/s0003598x00095697Cerrillo-Cuenca, E., & Sepúlveda, M. (2015). An assessment of methods for the digital enhancement of rock paintings: the rock art from the precordillera of Arica (Chile) as a case study. Journal of Archaeological Science, 55, 197-208. doi:10.1016/j.jas.2015.01.006Robert, E., Petrognani, S., & Lesvignes, E. (2016). Applications of digital photography in the study of Paleolithic cave art. Journal of Archaeological Science: Reports, 10, 847-858. doi:10.1016/j.jasrep.2016.07.026López-Menchero Bendicho, V. M., Marchante Ortega, Á., Vincent, M., Cárdenas Martín-Buitrago, Á. J., & Onrubia Pintado, J. (2017). Uso combinado de la fotografía digital nocturna y de la fotogrametría en los procesos de documentación de petroglifos: el caso de Alcázar de San Juan (Ciudad Real, España). Virtual Archaeology Review, 8(17), 64. doi:10.4995/var.2017.6820Molada-Tebar, A., Lerma, J. L., & Marqués-Mateu, Á. (2017). Camera characterization for improving color archaeological documentation. Color Research & Application, 43(1), 47-57. doi:10.1002/col.22152Del Hoyo-Meléndez, J. M., Lerma, J. L., López-Montalvo, E., & Villaverde, V. (2015). Documenting the light sensitivity of Spanish Levantine rock art paintings. ISPRS Annals of Photogrammetry, Remote Sensing and Spatial Information Sciences, II-5/W3, 53-59. doi:10.5194/isprsannals-ii-5-w3-53-2015Whitmore, P. M., Bailie, C., & Connors, S. A. (2000). Micro-fading tests to predict the result of exhibition: progress and prospects. Studies in Conservation, 45(sup1), 200-205. doi:10.1179/sic.2000.45.supplement-1.200Whitmore, P. M., Pan, X., & Bailie, C. (1999). Predicting the Fading of Objects: Identification of Fugitive Colorants through Direct Nondestructive Lightfastness Measurements. Journal of the American Institute for Conservation, 38(3), 395. doi:10.2307/3179999Ford, B. (2011). Non-destructive microfade testing at the National Museum of Australia. AICCM Bulletin, 32(1), 54-64. doi:10.1179/bac.2011.32.1.008Del Hoyo-Meléndez, J. M., & Mecklenburg, M. F. (2010). A survey on the light-fastness properties of organic-based Alaska Native artifacts. Journal of Cultural Heritage, 11(4), 493-499. doi:10.1016/j.culher.2010.01.004Conservation of Ancient Sites on the Silk Road 2010 The Getty Conservation Institute The Getty. Los Angeles JR Druzik Evaluating the light sensitivity of paints in selected wall paintings at the Mogao Grottoes: caves 217 98 and 85 457 463López-Montalvo, E., Roldán, C., Badal, E., Murcia-Mascarós, S., & Villaverde, V. (2017). Identification of plant cells in black pigments of prehistoric Spanish Levantine rock art by means of a multi-analytical approach. A new method for social identity materialization using chaîne opératoire. PLOS ONE, 12(2), e0172225. doi:10.1371/journal.pone.0172225Roldán, C., Murcia-Mascarós, S., Ferrero, J., Villaverde, V., López, E., Domingo, I., … Guillem, P. M. (2010). Application of field portable EDXRF spectrometry to analysis of pigments of Levantine rock art. X-Ray Spectrometry, 39(3), 243-250. doi:10.1002/xrs.1254Roldán García, C., Villaverde Bonilla, V., Ródenas Marín, I., & Murcia Mascarós, S. (2016). A Unique Collection of Palaeolithic Painted Portable Art: Characterization of Red and Yellow Pigments from the Parpalló Cave (Spain). PLOS ONE, 11(10), e0163565. doi:10.1371/journal.pone.0163565Łojewski, T., Thomas, J., Gołąb, R., Kawałko, J., & Łojewska, J. (2011). Note: Light ageing with simultaneous colorimetry via fibre optics reflection spectrometry. Review of Scientific Instruments, 82(7), 076102. doi:10.1063/1.3606645Ruppert, D., Wand, M. P., & Carroll, R. J. (2009). Semiparametric regression during 2003–2007. Electronic Journal of Statistics, 3(0), 1193-1256. doi:10.1214/09-ejs525ISO11664‐2:2007(E)/CIE S 014‐2/E:2006 Colorimetry—Part 2: Standard Illuminants for Colorimetry.http://cie.co.at/index.php?i_ca_id=484. Accessed October 25 2017.ISO11664‐1:2007(E)/CIE S 014‐1/E:2006 CIE Colorimetry—Part 1: Standard Colorimetric Observers.http://cie.co.at/index.php?i_ca_id=483. Accessed October 25 2017.Arkivprodukter. The Blue Wool Standards.www.arkivprodukter.no. Accessed November 23 2017.Bacci, M., Cucci, C., Mencaglia, A. A., Mignani, A. G., & Porcinai, S. (2004). Calibration and Use of Photosensitive Materials for Light Monitoring in Museums. Studies in Conservation, 49(2), 85-98. doi:10.1179/sic.2004.49.2.85ISO 12647‐2. International Standard for the Production of Half‐Tone Colour.2004;2004

    Cervical spondylosis with spinal cord encroachment: should preventive surgery be recommended?

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    <p>Abstract</p> <p>Background</p> <p>It has been stated that individuals who have spondylotic encroachment on the cervical spinal cord without myelopathy are at increased risk of spinal cord injury if they experience minor trauma. Preventive decompression surgery has been recommended for these individuals. The purpose of this paper is to provide the non-surgical spine specialist with information upon which to base advice to patients. The evidence behind claims of increased risk is investigated as well as the evidence regarding the risk of decompression surgery.</p> <p>Methods</p> <p>A literature search was conducted on the risk of spinal cord injury in individuals with asymptomatic cord encroachment and the risk and benefit of preventive decompression surgery.</p> <p>Results</p> <p>Three studies on the risk of spinal cord injury in this population met the inclusion criteria. All reported increased risk. However, none were prospective cohort studies or case-control studies, so the designs did not allow firm conclusions to be drawn. A number of studies and reviews of the risks and benefits of decompression surgery in patients with cervical myelopathy were found, but no studies were found that addressed surgery in asymptomatic individuals thought to be at risk. The complications of decompression surgery range from transient hoarseness to spinal cord injury, with rates ranging from 0.3% to 60%.</p> <p>Conclusion</p> <p>There is insufficient evidence that individuals with spondylotic spinal cord encroachment are at increased risk of spinal cord injury from minor trauma. Prospective cohort or case-control studies are needed to assess this risk. There is no evidence that prophylactic decompression surgery is helpful in this patient population. Decompression surgery appears to be helpful in patients with cervical myelopathy, but the significant risks may outweigh the unknown benefit in asymptomatic individuals. Thus, broad recommendations for decompression surgery in suspected at-risk individuals cannot be made. Recommendations to individual patients must consider possible unique circumstances.</p
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