26 research outputs found

    Geometries for Possible Kinematics

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    The algebras for all possible Lorentzian and Euclidean kinematics with so(3)\frak{so}(3) isotropy except static ones are re-classified. The geometries for algebras are presented by contraction approach. The relations among the geometries are revealed. Almost all geometries fall into pairs. There exists t↔1/(ν2t)t \leftrightarrow 1/(\nu^2t) correspondence in each pair. In the viewpoint of differential geometry, there are only 9 geometries, which have right signature and geometrical spatial isotropy. They are 3 relativistic geometries, 3 absolute-time geometries, and 3 absolute-space geometries.Comment: 40 pages, 7 figure

    Cluster-randomized controlled trial of the effects of free glasses on purchase of children's glasses in China:The PRICE (Potentiating Rural Investment in Children's Eyecare) study

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    Offering free glasses can be important to increase children's wear. We sought to assess whether "Upgrade glasses" could avoid reduced glasses sales when offering free glasses to children in China.In this cluster-randomized, controlled trial, children with uncorrected visual acuity (VA)6/12 in both eyes at 138 randomly-selected primary schools in 9 counties in Guangdong and Yunnan provinces, China, were randomized by school to one of four groups: glasses prescription only (Control); Free Glasses; Free Glasses + offer of 15UpgradeGlasses;FreeGlasses+offerof15 Upgrade Glasses; Free Glasses + offer of 30 Upgrade Glasses. Spectacle purchase (main outcome) was assessed 6 months after randomization.Among 10,234 children screened, 882 (8.62%, mean age 10.6 years, 45.5% boys) were eligible and randomized: 257 (29.1%) at 37 schools to Control; 253 (28.7%) at 32 schools to Free Glasses; 187 (21.2%) at 31 schools to Free Glasses + 15Upgrade;and185(21.015 Upgrade; and 185 (21.0%) at 27 schools to Free Glasses +30 Upgrade. Baseline ownership among these children needing glasses was 11.8% (104/882), and 867 (98.3%) children completed follow-up. Glasses purchase was significantly less likely when free glasses were given: Control: 59/250 = 23.6%; Free glasses: 32/252 = 12.7%, P = 0.010. Offering Upgrade Glasses eliminated this difference: Free + 15Upgrade:39/183=21.315 Upgrade: 39/183 = 21.3%, multiple regression relative risk (RR) 0.90 (0.56-1.43), P = 0.65; Free + 30 Upgrade: 38/182 = 20.9%, RR 0.91 (0.59, 1.42), P = 0.69.Upgrade glasses can prevent reductions in glasses purchase when free spectacles are provided, providing important program income.ClinicalTrials.gov Identifier: NCT02231606. Registered on 31 August 2014

    Finishing the euchromatic sequence of the human genome

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    The sequence of the human genome encodes the genetic instructions for human physiology, as well as rich information about human evolution. In 2001, the International Human Genome Sequencing Consortium reported a draft sequence of the euchromatic portion of the human genome. Since then, the international collaboration has worked to convert this draft into a genome sequence with high accuracy and nearly complete coverage. Here, we report the result of this finishing process. The current genome sequence (Build 35) contains 2.85 billion nucleotides interrupted by only 341 gaps. It covers ∼99% of the euchromatic genome and is accurate to an error rate of ∼1 event per 100,000 bases. Many of the remaining euchromatic gaps are associated with segmental duplications and will require focused work with new methods. The near-complete sequence, the first for a vertebrate, greatly improves the precision of biological analyses of the human genome including studies of gene number, birth and death. Notably, the human enome seems to encode only 20,000-25,000 protein-coding genes. The genome sequence reported here should serve as a firm foundation for biomedical research in the decades ahead

    A Systematic Review of Serious Games for Collaborative Learning: Theoretical Framework, Game Mechanic and Efficiency Assessment

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    In recent years, there has been extensive research on serious games for edu-cational purpose. However, the design space for collaboration in games re-mains substantially unexplored. In this study, we systematically reviewed 31 empirical research articles regarding game-based collaborative learning published from 2006 to 2020 and attempted to provide new information about designing serious games for collaborative learning. We surveyed a number of games and investigated their design features that encourage col-laborative learning. Twenty game mechanics were identified and grouped in-to six main domains: (1) Space, (2) Objects, attributes and states, (3) Ac-tions, (4) Rules and goals, (5) Skill, (6) chance. The analysis of user studies they performed indicated that most of the game projects relied on self-report methods to test their learning effectiveness, and only a few studies adopted the data mining method based on game logs. The implications for research into facilitating collaborative learning and recommendations for future re-search directions are discussed

    Application of Geodesign Techniques for Ecological Engineered Landscaping of Urban River Wetlands: A Case Study of Yuhangtang River

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    Although geodesign techniques have been studied and developed worldwide, there is still a lack of in-depth application of geodesign workflows for redesigning urban river wetlands with characteristics of ecologically engineered landscaping (EEL). The study mainly aims at putting forward a proper approach in the methodological foundation for EEL practices in river wetlands. A typical EEL-oriented project of river restoration in Hangzhou, China, was conducted in this study. Based on in-situ geodata and tools within QGIS, individual geological factors analysis, with the hierarchical analysis method (AHP) and ecological vulnerability evaluation (EVE), was conducted by experts’ voting and the weighted linear combination (WLC) method. Analysis of hydrological-related factors proceeded. This GIS-based analysis with expert knowledge provided comprehensive redesign solutions for the redesign project, i.e., restoration of the riverbed, spatial restoration in the horizontal and vertical dimensions, and integration with the multifunctional design. Detailed three-dimensional models for design practices were developed to present redesigned topology and space accordingly. Terrain, inundation, and visibility analysis proceeded with parametric mapping programs within Grasshopper to check the feasibility. The adapted geodesign-based workflow in the study also applies to the site analysis, sustainable assessment and landscape planning for urban wetlands EEL projects

    Application of Geodesign Techniques for Ecological Engineered Landscaping of Urban River Wetlands: A Case Study of Yuhangtang River

    No full text
    Although geodesign techniques have been studied and developed worldwide, there is still a lack of in-depth application of geodesign workflows for redesigning urban river wetlands with characteristics of ecologically engineered landscaping (EEL). The study mainly aims at putting forward a proper approach in the methodological foundation for EEL practices in river wetlands. A typical EEL-oriented project of river restoration in Hangzhou, China, was conducted in this study. Based on in-situ geodata and tools within QGIS, individual geological factors analysis, with the hierarchical analysis method (AHP) and ecological vulnerability evaluation (EVE), was conducted by experts’ voting and the weighted linear combination (WLC) method. Analysis of hydrological-related factors proceeded. This GIS-based analysis with expert knowledge provided comprehensive redesign solutions for the redesign project, i.e., restoration of the riverbed, spatial restoration in the horizontal and vertical dimensions, and integration with the multifunctional design. Detailed three-dimensional models for design practices were developed to present redesigned topology and space accordingly. Terrain, inundation, and visibility analysis proceeded with parametric mapping programs within Grasshopper to check the feasibility. The adapted geodesign-based workflow in the study also applies to the site analysis, sustainable assessment and landscape planning for urban wetlands EEL projects

    Development of a Virtual Reality Game for Cultural Heritage Education: The Voyage of 'Gotheborg'

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    Video games have been recognized as one of the most engaging forms of entertainment today, and are making a major contribution to the digital future. This research aims to combine the gaming elements of game design and virtual reality technology, and promote cultural heritage education through an engaging and fun experience, especially in a young population. Firstly, we summarized game mechanics and elements used for cultural heritage education through game product analysis and literature review. Secondly, we developed a virtual reality game for cultural heritage education that reproduced the voyage of 'Gotheborg' to Canton, including game mechanic, game story, aesthetic expression and game technology. Finally, a pilot test was conducted to validate the effectiveness of our game developed. Our study contributes interdisciplinary research by bringing together currently distinct approaches from virtual reality technology, game design, cultural heritage, and education. It will bring new technology to impact on the digital media, cultural heritage education, and service industries

    Association between the insulin resistance and all-cause mortality in patients with moderate and severe aortic stenosis: a retrospective cohort study

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    Abstract Background The triglyceride-glucose (TyG) index is a reliable surrogate marker of insulin resistance (IR). However, whether the TyG index has prognostic value in patients with moderate to severe aortic stenosis (AS) remains unclear. Methods This study enrolled 317 patients with moderate to severe AS at the First Affiliated Hospital of Sun Yat-Sen University. The patients were grouped according to the cut-off value of the TyG index. Cox regression with Firth’s penalized maximum likelihood method and restricted cubic splines regression were conducted to assess the association between the TyG index and all-cause mortality. The added value of the TyG index included in the traditional risk factors model for outcome prediction was also analyzed. Results Among 317 patients (mean age 67.70 years, 62.8% male), there was 84 all-cause mortality during a median 38.07 months follow-up. After fully adjusting for confounders, a per-unit increase in the TyG index was associated with a 62% higher all-cause mortality risk (HR 1.622, 95% CI 1.086–2.416, p = 0.018). The restricted cubic splines regression model revealed a linear association between the TyG index and the risk of all-cause mortality (p for nonlinearity = 0.632). The addition of the TyG index in the basic risk model has an incremental effect on the prediction of mortality [C-statistic change from 0.755 to 0.768; continuous net reclassification improvement (95% CI): 0.299 (0.051–0.546), p = 0.017; integrated discrimination improvement: 0.017 (0.001–0.033), p = 0.044]. Conclusions Higher IR assessed by the TyG index was associated with a higher risk of all-cause mortality in patients with moderate and severe AS
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