3,192 research outputs found

    QCD calculation of J/psi+gamma mass distributions

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    We compute the J/psi+gamma invariant-mass distributions from the QCD subprocess g + g --> J/psi+gamma. At large masses, this subprocess is the dominant mechanism for J/psi+gamma production, and data could provide a good test of QCD. The mass distribution peaks at relatively small masses (3.4 - 4.0 GeV) and the subprocess could, therefore, represent a significant QCD background to J/psi+gamma decay of heavier charmonia. We also analyze the J/psi angular distribution in the J/psi+gamma rest frame.Comment: 7 pages LaTex, 4 figures available on request. CERN-TH.6974/93, ANL-HEP-PR-93.6

    Band structure of W and Mo by empirical pseudopotential method

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    The empirical pseudopotential method (EPM) is used to calculate the band structure of tungsten and molybdenum. Agreement between the calculated reflectivity, density of states, density of states at the Fermi surface and location of the Fermi surface from this study and experimental measurements and previous calculations is good. Also the charge distribution shows the proper topological distribution of charge for a bcc crystal

    A parallel implementation of a multisensor feature-based range-estimation method

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    There are many proposed vision based methods to perform obstacle detection and avoidance for autonomous or semi-autonomous vehicles. All methods, however, will require very high processing rates to achieve real time performance. A system capable of supporting autonomous helicopter navigation will need to extract obstacle information from imagery at rates varying from ten frames per second to thirty or more frames per second depending on the vehicle speed. Such a system will need to sustain billions of operations per second. To reach such high processing rates using current technology, a parallel implementation of the obstacle detection/ranging method is required. This paper describes an efficient and flexible parallel implementation of a multisensor feature-based range-estimation algorithm, targeted for helicopter flight, realized on both a distributed-memory and shared-memory parallel computer

    Response to sub-threshold stimulus is enhanced by spatially heterogeneous activity

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    Sub-threshold stimuli cannot initiate excitations in active media, but surprisingly as we show in this paper, they can alter the time-evolution of spatially heterogeneous activity by modifying the recovery dynamics. This results in significant reduction of waveback velocity which may lead to spatial coherence, terminating all activity in the medium including spatiotemporal chaos. We analytically derive model-independent conditions for which such behavior can be observed.Comment: 5 pages, 5 figure

    Boston Hospitality Review: Spring 2018

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    Table of contents: Sustainability In Hospitality? How Legality and Authenticity Impact the Rationale for Integrating Sustainable Practices By Christian E. Hardigree, J.D. -- The Digital Future of the Tourism & Hospitality Industry By Martin Zsarnoczky -- Cutting Through the Online Hospitality Clutter, Part II: Best Practices for Paid Digital Marketing By Leora Lanz and Namrata Sridhar -- Blending Theory and Practice: Experiential Learning in Hospitality Curriculum: A Case Study of Student Projects for Industry Clients By Michael Oshins and Joel Brown

    Gamma^*, Z^* production in polarised p-p scattering as a probe of the proton spin structure

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    We present the results of a detailed study of the large transverse momentum Drell-Yan process, pp --> (Gamma^*, Z^*)X --> l^+l^- X at collider energies, with either one or both protons polarised, allowing the study of single- and double-spin asymmetries respectively. We show how these asymmetries obtained from angular distributions of the leptons in the Gamma^* (or Z^*) rest-frame, can be used to get information on the polarised parton distributions. Numerical results for the asymmetries and the cross-sections are presented, and the sensitivity of the asymmetries to the initial parton distributions indicates that these can be used as effective probes of the spin structure of the proton.Comment: Latex, 9 pages, 4 figures available on request, CERN-TH.6997/9

    Relative contributions of the two eyes to perceived egocentric visual direction in normal binocular vision

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    AbstractPerceived egocentric direction (EVD) is based on the sensed position of the eyes in the orbit and the oculocentric visual direction (eye-centered, OVD). Previous reports indicate that in some subjects eye-position information from the two eyes contributes unequally to the perceived EVD. Findings from other studies indicate that the retinal information from the two eyes may not always contribute equally to perceived OVD. The goal of this study was to assess whether these two sources of information covary similarly within the same individuals. Open-loop pointing responses to an isolated target presented randomly at several horizontal locations were collected from 13 subjects during different magnitudes of asymmetric vergence to estimate the contribution of the position information from each eye to perceived EVD. For the same subjects, the direction at which a horizontally or vertically disparate target with different interocular contrast or luminance ratios appeared aligned with a non-disparate target estimated the relative contribution of each eye’s retinal information. The results show that the eye-position and retinal information vary similarly in most subjects, which is consistent with a modified version of Hering’s law of visual direction

    ANTI INFLAMMATORY EFFECT OF CIPROFLOXACIN, AZITHROMYCIN AND DICLOFENAC SODIUM ON CARRAGEENAN INDUCED HIND PAW EDEMA IN MICE

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    Background: Obviously, antibacterial agents are primarily directed against bacteria. However, because microorganisms can initiate an exaggerated inflammatory reaction, and as pathogens which persist in cryptic reservoirs (cells or granuloma tissue) can be the underlying cause of chronic inflammation, the hypothesis that antibacterials can down regulate inflammation. Methodology: Healthy adult mice weighing 20 - 30 g and aged 6-8 weeks, each group 6 mice were included. 1% carrageenan administered to produce inflammation. Grouping: Group 1: Normal saline 0.2 ml. i.p., Group 2: Diclofenac sodium 25mg/kg, Group 3 Ciprofloxacin 50 mg/kg, Group 4: Azithromycin 20mg/kg. Drugs were administered Intra Peritoneal. After 30 min of test drugs administration each group of mice were received subplantar administration of 0.05ml of saline (Control) or 0.05ml carrageenan (1%) for test groups 2 to 4. Paw volumes were measured by dipping in to the mercury plethysmograph at 30, 60, 120 and 180 minutes and results were tabulated. Results: Diclofenac, ciproflaoxin, Azithromycin inhibited paw edema in % at 30min 42.85, 28.55, 14.28, at 60min 75, 50, 25, at 120min 71.42, 42.85, 14.28, and at 180 min 50, 50, 25 respectively. Conclusion: Ciprofloxacin (50mg/kg) has exhibited consistent anti-inflammatory, but the anti-inflammatory activity of is less than that of Diclofenac sodium and Azithromycin also has exhibited anti-inflammatory activity, though much less when compared to Diclofenac sodium and Ciprofloxacin. Key words: Anti inflammatory effect; Azithromycin; Ciprofloxacin; Diclofenac Sodium; Paw edema; Mice

    Role of CEACAM1, ECM, and Mesenchymal Stem Cells in an Orthotopic Model of Human Breast Cancer

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    Carcinoembryonic antigen-related cell adhesion molecule-1 (CEACAM1) is a morphogen in an in vitro model for lumen formation and plays a similar role in breast epithelial cells implanted in humanized mammary fat pads in NOD-SCID mice. Although extra cellular matrix alone is sufficient to stimulate lumen formation in CEACAM1 transfected MCF-7 cells grown in 3D culture, there is an additional requirement for stromal or mesenchymal cells (MSCs) for these cells to form xenografts with glandular structures in an orthotopic site. We demonstrate that optimal in vitro conditions include both Matrigel and MSCs and that the inclusion of collagen I inhibits xenograft differentiation. Additionally, there is no need to remove the nascent murine mammary gland. The previously observed difference in gland development between the long and short cytoplasmic domain isoforms of CEACAM1 is no longer observed in pregnant NOD/SCID mice suggesting that stimulation of the mammary fat pad by pregnancy critically affects xenograft differentiation
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