11,993 research outputs found

    Planck Fluctuations, Measurement Uncertainties and the Holographic Principle

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    Starting from a critical analysis of recently reported surprisingly large uncertainties in length and position measurements deduced within the framework of quantum gravity, we embark on an investigation both of the correlation structure of Planck scale fluctuations and the role the holographic hypothesis is possibly playing in this context. While we prove the logical independence of the fluctuation results and the holographic hypothesis (in contrast to some recent statements in that direction) we show that by combining these two topics one can draw quite strong and interesting conclusions about the fluctuation structure and the microscopic dynamics on the Planck scale. We further argue that these findings point to a possibly new and generalized form of quantum statistical mechanics of strongly (anti)correlated systems of degrees of freedom in this fundamental regime.Comment: 19 pages, Latex, no figures, some new references, to appear ModPhysLett

    Survival of the NASA Mars Odyssey isolate Acinetobacter radioresistens 50v1 on different spaceflight relevant antimicrobial surfaces

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    Since many years, human mankind travels to space. One of our mayor interests is the health of astronauts and the protection of the spacecraft. Apart from external influences, the microbial burden inside of the International Space Station (ISS) may be dangerous and must be limited to a minimum. To ensure the status and the protection of the crew as well as the spacecraft itself, it is necessary to determine the survival of microorganisms on different surfaces. Microorganisms are constantly changing their strategy of survival, primarily induced by extreme environmental conditions, such as space conditions, compared to their terrestrial habitats. However, the increased levels in resistance and robustness possibly play a sensitive role in evolving new virulence factors in the space environment. One of the bacteria on the NASA Mars Odyssey spacecraft, which have been isolated, is the Gram-negative, non-motile bacterium Acinetobacter radioresistens. Apart from Deinococcus radiodurans, A. radioresistens shows similar levels in radiation and oxidative stress tolerance (McCoy et al., 2012). In our work, we used the strain 50v1, isolated from the surface of the Mars Odyssey spacecraft as well as the type strain DSM6976, which was isolated on Earth from cotton and soil samples. We investigated the resistance regarding in their desiccation tolerance on metallic surfaces including materials with different antimicrobial properties. For those experiments we exposed and desiccated both strains on the different surfaces (such as copperand silver-containing materials) and determined the survival over different time points. First results show a high resistance of the spacecraft isolated strain compared to the type strain. These results give implications about the higher survivability of environmental microorganisms and highlight the essence of bioburden reduction and improve sterilization approaches/techniques for upcoming space exploration missions towards the search for life outside Earth

    Deep Eyes: Binocular Depth-from-Focus on Focal Stack Pairs

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    Human visual system relies on both binocular stereo cues and monocular focusness cues to gain effective 3D perception. In computer vision, the two problems are traditionally solved in separate tracks. In this paper, we present a unified learning-based technique that simultaneously uses both types of cues for depth inference. Specifically, we use a pair of focal stacks as input to emulate human perception. We first construct a comprehensive focal stack training dataset synthesized by depth-guided light field rendering. We then construct three individual networks: a Focus-Net to extract depth from a single focal stack, a EDoF-Net to obtain the extended depth of field (EDoF) image from the focal stack, and a Stereo-Net to conduct stereo matching. We show how to integrate them into a unified BDfF-Net to obtain high-quality depth maps. Comprehensive experiments show that our approach outperforms the state-of-the-art in both accuracy and speed and effectively emulates human vision systems

    Short Courses: Flexible Learning Opportunities in Informatics

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    In today’s fast-paced, data-driven world, researchers need to have a good foundation in informatics to store, organize, process, and analyze growing amounts of data. However, not all degree programs offer such training. Obtaining training in informatics on your own can be a daunting task for both new and established researchers who have little informatics experience. Providing educational opportunities appropriate for various skill levels and that mesh with a full-time schedule can remove barriers and foster a collaborative, informatics-savvy community that is better equipped to push science forward. To enhance informatics education in bioinformatics, VCUs Wright Center for Clinical and Translational Research of- fers a complementary series of seminars and workshops. These short course offerings introduce attendees to bioinformatics concepts and applications, and provide hands-on experience using online Bioinformatics databases. Bioinformatics 101 (B101) is an 8-week long series of 1-hour seminars focused on introducing topics in bioinformatics related to Next Generation Sequencing (NGS). Lectures are application focused and include overviews of NGS technology, practical bioinformatics pipelines, and examples of how the technology can influence downstream bioinformatics analyses. Bioinformatics 102 (B102) is a 5-day, 2 hours per day workshop developed in collaboration with VCU Libraries that provides attendees with hands-on experience accessing and using public data repositories. Sessions include a brief lecture followed by hands-on exercises. A Certificate of Completion is awarded upon meeting certain criteria for either the 101 or 102 courses. Bioinformatics 101 has been offered 3 times with a combined total of 246 registrants, and Bioinformatics 102 has been offered twice with a total of 78 registrants (limited to 30 per session per day). From course surveys, 82% (n=108) and 95% (n=47) of respondents gave B101 and B102 a positive rating, respectively. In addition, 89% of B101 respondents indicated their knowledge was improved, with 100% of B102 respondents indicating the same. A total of 84 and 33 certificates have been awarded for B101 and B102, respectively. The Bioinformatics 101 and 102 courses have become highly anticipated across the university, and have gained the external attention of surrounding businesses and colleges. Registrants have diverse backgrounds including biological, clinical, computational, administrative, librarian, business, and others with a total of 77 departments across VCU and VCU Health represented. Due to this interest, Bioinformatics 101 began offering live online attendance to accommodate those who were unable to travel across campus, or who are attending from outside VCU. This past year, 50% of attendance was online indicating a growing need for flexible education opportunities in informatics. Increasing researcher knowledge of Bioinformatics along with awareness of university resources for informatics support fosters an informatics-savvy research community that is empowered to take advantage of existing and new data sources in the pursuit of new insights and scientific discoveries for the betterment of human health. Future work will include the development of a more comprehensive educational framework by creating new and flexible learning opportunities that will make informatics education easy and convenient for our dedicated researchers

    Half-lives of rp-process waiting point nuclei

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    We give results of microscopic calculations for the half-lives of various proton-rich nuclei in the mass region A=60-90, which are involved in the astrophysical rp-process, and which are needed as input parameters of numerical simulations in Nuclear Astrophysics. The microscopic formalism consists of a deformed QRPA approach that involves a selfconsistent quasiparticle deformed Skyrme Hartree-Fock basis and residual spin-isospin separable forces in both the particle-hole and particle-particle channels. The strength of the particle-hole residual interaction is chosen to be consistent with the Skyrme effective force and mean field basis, while that of the particle-particle is globally fixed to 0.07 MeV after a judicious choice from comparison to experimental half-lives. We study and discuss the sensitivity of the half-lives to deformation and residual interactions.Comment: 8 pages, 4 figures, to be published in Eur. Phys. J.
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