53 research outputs found

    Design of a multiuser virtual trade fair using a game engine

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    The current world economic situation makes it necessary to develop new ways of establishing commercial relationships. One possible solution is to explore the advantages of virtual worlds, and for this reason online virtual trade fairs are becoming more popular in the business world. They enable companies to establish a trade relationship with their customers without the need to visit them in person. This is very attractive for exhibitors because it can save them money, which is a priority for many companies today. In this line, this article presents a multiuser virtual trade fair developed using 3D game engine technologys. Users represented by avatars can interact with each other while they are visiting the virtual fair, which has some interactive objects included in the stands to provide information about the exhibitors. This virtual world is accessible online, and visitors only require a plug-in on their computers to be able to enter the virtual world. The game technology makes it possible to obtain a high degree of realism: very real lighting, cast shadows, collision detection, etc. Moreover, the virtual world presented builds the 3D objects automatically. Participants in the trade fair can customize their virtual stand and the application will generate the code necessary for its inclusion in the rendered virtual world.This work was supported by the Spanish Ministry of Science and Technology project TIN2010-21089-C03-03. And also by Bancaja, project P1 1B2007-5

    HI in the Outskirts of Nearby Galaxies

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    The HI in disk galaxies frequently extends beyond the optical image, and can trace the dark matter there. I briefly highlight the history of high spatial resolution HI imaging, the contribution it made to the dark matter problem, and the current tension between several dynamical methods to break the disk-halo degeneracy. I then turn to the flaring problem, which could in principle probe the shape of the dark halo. Instead, however, a lot of attention is now devoted to understanding the role of gas accretion via galactic fountains. The current Λ\rm \Lambda cold dark matter theory has problems on galactic scales, such as the core-cusp problem, which can be addressed with HI observations of dwarf galaxies. For a similar range in rotation velocities, galaxies of type Sd have thin disks, while those of type Im are much thicker. After a few comments on modified Newtonian dynamics and on irregular galaxies, I close with statistics on the HI extent of galaxies.Comment: 38 pages, 17 figures, invited review, book chapter in "Outskirts of Galaxies", Eds. J. H. Knapen, J. C. Lee and A. Gil de Paz, Astrophysics and Space Science Library, Springer, in pres

    Alcohol intake and colorectal cancer : a pooled analysis of 8 cohort studies

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    BACKGROUND: Epidemiologic studies have generally reported positive associations between alcohol consumption and risk for colorectal cancer. However, findings related to specific alcoholic beverages or different anatomic sites in the large bowel have been inconsistent. OBJECTIVE: To examine the relationship of total alcohol intake and intake from specific beverages to the incidence of colorectal cancer and to evaluate whether other potential risk factors modify the association. DESIGN: Pooled analysis of primary data from 8 cohort studies in 5 countries. SETTING: North America and Europe. PARTICIPANTS: 489,979 women and men with no history of cancer other than nonmelanoma skin cancer at baseline. MEASUREMENTS: Alcohol intake was assessed in each study at baseline by using a validated food-frequency questionnaire. RESULTS: During a maximum of 6 to 16 years of follow-up across the studies, 4687 cases of colorectal cancer were documented. In categorical analyses, increased risk for colorectal cancer was limited to persons with an alcohol intake of 30 g/d or greater (approximately > or =2 drinks/d), a consumption level reported by 4% of women and 13% of men. Compared with nondrinkers, the pooled multivariate relative risks were 1.16 (95% CI, 0.99 to 1.36) for persons who consumed 30 to less than 45 g/d and 1.41 (CI, 1.16 to 1.72) for those who consumed 45 g/d or greater. No significant heterogeneity by study or sex was observed. The association was evident for cancer of the proximal colon, distal colon, and rectum. No clear difference in relative risks was found among specific alcoholic beverages. LIMITATIONS: The study included only one measure of alcohol consumption at baseline and could not investigate lifetime alcohol consumption, alcohol consumption at younger ages, or changes in alcohol consumption during follow-up. It also could not examine drinking patterns or duration of alcohol use. CONCLUSIONS: A single determination of alcohol intake correlated with a modest relative elevation in colorectal cancer rate, mainly at the highest levels of alcohol intake
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