2,970 research outputs found

    Kernel-based high-dimensional histogram estimation for visual tracking

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    ©2008 IEEE. Personal use of this material is permitted. However, permission to reprint/republish this material for advertising or promotional purposes or for creating new collective works for resale or distribution to servers or lists, or to reuse any copyrighted component of this work in other works must be obtained from the IEEE. This material is presented to ensure timely dissemination of scholarly and technical work. Copyright and all rights therein are retained by authors or by other copyright holders. All persons copying this information are expected to adhere to the terms and constraints invoked by each author's copyright. In most cases, these works may not be reposted without the explicit permission of the copyright holder.Presented at the 15th IEEE International Conference on Image Processing, October 12–15, 2008, San Diego, California, U.S.A.DOI: 10.1109/ICIP.2008.4711862We propose an approach for non-rigid tracking that represents objects by their set of distribution parameters. Compared to joint histogram representations, a set of parameters such as mixed moments provides a significantly reduced size representation. The discriminating power is comparable to that of the corresponding full high dimensional histogram yet at far less spatial and computational complexity. The proposed method is robust in the presence of noise and illumination changes, and provides a natural extension to the use of mixture models. Experiments demonstrate that the proposed method outperforms both full color mean-shift and global covariance searches

    Results from RHIC with Implications for LHC

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    Results from the PHENIX experiment at RHIC in p-p and Au+Au collisions are reviewed from the perspective of measurements in p-p collisions at the CERN-ISR which serve as a basis for many of the techniques used. Issues such as J/Psi suppression and hydrodynamical flow in A+A collisions require data from LHC-Ions for an improved understanding. Suppression of high pT particles in Au+Au collisions, first observed at RHIC, also has unresolved mysteries such as the equality of the suppression of inclusive pi0 (from light quarks and gluons) and direct-single electrons (from the decay of heavy quarks) in the transverse momentum range 4< pT < 9 GeV/c. This disfavors a radiative explanation of suppression and leads to a fundamental question of whether the Higgs boson gives mass to fermions. Observation of an exponential distribution of direct photons in central Au+Au collisions for 1< pT <2 GeV/c where hard-processes are negligible and with no similar exponential distribution in p-p collisions indicates thermal photon emission from the medium at RHIC, making PHENIX at the moment ``the hottest experiment in Physics''.Comment: Invited lectures at the International School of Subnuclear Physics, 47th Course, "The most unexpected at LHC and the status of High Energy Frontier'', Erice, Sicily, Italy, August 29-September 7. 2009. 32 pages, 22 figure

    A fundamental test of the Higgs Yukawa coupling at RHIC in A+A collisions

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    Searches for the intermediate boson, W±W^{\pm}, the heavy quantum of the Weak Interaction, via its semi-leptonic decay, W→e+νW\to e +\nu, in the 1970's instead discovered unexpectedly large hadron production at high pTp_T, notably π0\pi^0, which provided a huge background of e±e^{\pm} from internal and external conversions. Methods developed at the CERN ISR which led to the discovery of direct-single-e±e^{\pm} in 1974, later determined to be from the semi-leptonic decay of charm which had not yet been discovered, were used by PHENIX at RHIC to make precision measurements of heavy quark production in p-p and Au+Au collisions, leading to the puzzle of apparent equal suppression of light and heavy quarks in the QGP. If the Higgs mechanism gives mass to gauge bosons but not to fermions, then a proposal that all 6 quarks are nearly massless in a QGP, which would resolve the puzzle, can not be excluded. This proposal can be tested with future measurements of heavy quark correlations in A+A collisionsComment: 12 pages, 16 figures, 26th Winter Workshop on Nuclear Dynamics, Ocho Rios, Jamaica WI, January 2-9, 2010. Corrected citation of 1974 direct single lepton discover

    Infection, inflammation and colon carcinogenesis

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    The importance of chronic inflammation as a risk factor for major cancers is well documented [1], and the inflammatory state is known to involve contributions of both adaptive and innate immune components. In a recent publication [2] we describe an experimental animal model in which infection, inflammation and cancer are mechanistically linked, and provide evidence that chemical mediators of the innate immune system and bacterial toxins both play key roles in driving colon carcinogenesis. In this model, epithelial injury caused by Helicobacter hepaticus infection enhances access of bacterially-associated products to pattern-recognition receptors located on surfaces of macrophages and dendritic cells. Receptor ligation leads to activation of transcription factors, including NF-kappa B, that regulate production of chemo-attractants for macrophages and neutrophils, recruitment of which is a hallmark of inflammation. These acute inflammatory events are re-enforced by expression of powerful inflammatory mediators such as TNF-α and IL-2, which amplify acute inflammatory gene expression and enhance cell survival. If not properly extinguished, the innate inflammatory response is maintained and further amplified by activation of cell-mediated adaptive immunity

    Serum Metabolomics in a Helicobacter hepaticus Mouse Model of Inflammatory Bowel Disease Reveal Important Changes in the Microbiome, Serum Peptides, and Intermediary Metabolism

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    Inflammatory bowel disease (IBD) is a chronic relapsing inflammatory disorder of the bowel. The etiology remains unknown, but IBD is immune-driven and multiple factors including genetic, environmental, and microbiological components play a role. Recombinase-activating gene-2-deficient (Rag2–/–) mice infected with Helicobacter hepaticus (H. hepaticus) have been developed as an animal model to imitate naturally occurring inflammatory events and associated key features of chronic inflammatory responses in humans. In this study, we have combined mass spectrometry-based metabolomics and peptidomics to analyze serum samples of Rag2–/– mice infected with H. hepaticus. Metabolomics profiling revealed that H. hepaticus infection dramatically changed numerous metabolite pathways, including tryptophan metabolism, glycerophospholipids, methionine-homocysteine cycle, citrate cycle, fatty acid metabolism and purine metabolism, with the majority of metabolites being down-regulated. In particular, there were notable effects of gut microflora on the blood metabolites in infected animals. In addition, the peptidomics approach identified a number of peptides, originating from proteins, including fibrinogen, complement C4, and alpha-2-macroglobulin, with diverse biological functions with potentially important implications for the progress of IBD. In summary, the strategy of integrating a relevant animal model and sensitive mass spectrometry-based profiling may offer a new perspective to explore biomarkers and provide mechanistic insights into IBD.National Institute of Environmental Health Sciences (MIT Center for Environmental Health Sciences, NIEHS grant (Grant No. ES002109))Massachusetts Institute of Technology (MIT-Merck Fellowship

    Debye screening in strongly coupled N=4 supersymmetric Yang-Mills plasma

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    Using the AdS/CFT correspondence, we examine the behavior of correlators of Polyakov loops and other operators in N=4 supersymmetric Yang-Mills theory at non-zero temperature. The implications for Debye screening in this strongly coupled non-Abelian plasma, and comparisons with available results for thermal QCD, are discussed.Comment: 21 pages, 5 figures, significantly expanded discussion of Polyakov loop correlator and static quark-antiquark potentia

    BEAMS Lab at MIT: Status report

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    The Biological Engineering Accelerator Mass Spectrometry (BEAMS) Lab at the Massachusetts Institute of Technology is a facility dedicated to incorporating AMS into life sciences research. As such, it is focused exclusively on radiocarbon and tritium AMS and makes use of a particularly compact instrument of a size compatible with most laboratory space. Recent developments at the BEAMS Lab were aimed to improve different stages of the measurement process, such as the carbon sample injection interface, the simultaneous detection of tritium and hydrogen and finally, the overall operation of the system. Upgrades and results of those efforts are presented here.United States. National Institutes of Health (grant P30-ES02109)United States. National Institutes of Health (grant R42-CA084688)National Institutes of Health. National Center for Research Resources (grant UL1 RR 025005)GlaxoSmithKlin
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