2,314 research outputs found

    Citizen Science & Open Science Community of Practice: Inception Report

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    Detection of Cherenkov light from air showers with Geiger-APDs

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    We have detected Cherenkov light from air showers with Geiger-mode APDs (G-APDs). G-APDs are novel semiconductor photon-detectors, which offer several advantages compared to conventional photomultiplier tubes in the field of ground-based gamma-ray astronomy. In a field test with the MAGIC telescope we have tested the efficiency of a G-APD / light catcher setup to detect Cherenkov light from air showers. We estimate a detection efficiency, which is 60% higher than the efficiency of a MAGIC camera pixel. Ambient temperature dark count rates of the tested G-APDs are below the rates of the night sky light background. According to these recent tests G-APDs promise a major progress in ground-based gamma-ray astronomy.Comment: 4 pages, 5 figures, to appear in the proceedings of the 30th International Cosmic Ray Conference, Merida, July 200

    The repertory of bone marrow progenitor cells associated with lymphogenic metastasis in patients with invasive carcinoma of no special type

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    The high mortality of patients with breast cancer is determined by metastatic disease. It is thought that the metastatic disease development associated with the repertory of bone marrow progenitor cells in breast cancer patients. In our study the correlation between the bone marrow progenitor cells presences in the tumor and blood of patients and the lymphogenic metastasis development was studied. The main clinical and pathological parameters of 24 patients with invasive breast carcinoma of non-specific type were analyzed. Endothelial progenitor cells, mesenchymal stem cells, macrophage precursors, hematopoietic progenitor cells were detected with specific antibodies against CD34, CD133, CD90, VEGFR1, CD11b, CD45, CD202 in the cell-rich fluid from frozen tumor. The amount of MCP-1 in the patients blood serum was assessed by enzymelinked immunosorbent assay (ELISA), at a wavelength of 450 nm. The cytokines concentration was calculated from the calibration plot. The program package Statistica 10.0. was used for statistical data processing. The high risk of lymphogenic metastasis in patients who didn't complete a neoadjuvant chemotherapy course was associated with the number of HPC, EPC and MSC in tumor and MCP-1 in blood

    Identification of the Beutler-Fano formula in eigenphase shifts and eigentime delays near a resonance

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    Eigenphase shifts and eigentime delays near a resonance for a system of one discrete state and two continua are shown to be functionals of the Beutler- Fano formulas using appropriate dimensionless energy units and line profile indices. Parameters responsible for the avoided crossing of eigenphase shifts and eigentime delays are identified. Similarly, parameters responsible for the eigentime delays due to a frame change are identified. With the help of new parameters, an analogy with the spin model is pursued for the S matrix and time delay matrix. The time delay matrix is shown to comprise three terms, one due to resonance, one due to a avoided crossing interaction, and one due to a frame change. It is found that the squared sum of time delays due to the avoided crossing interaction and frame change is unity.Comment: 17 pages, 3 figures, RevTe

    Weak Boson Production Amplitude Zeros; Equalities of the Helicity Amplitudes

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    We investigate the radiation amplitude zeros exhibited by many Standard Model amplitudes for triple weak gauge boson production processes. We show that WZγWZ\gamma production amplitudes have especially rich structure in terms of zeros, these amplitudes have zeros originating from several different sources. It is also shown that TYPE I current null zone is the special case of the equality of the specific helicity amplitudes.Comment: 27 pages, 12 figures, 2 table
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