53,304 research outputs found

    Lensing Magnification and QSO-Galaxy Cross-Correlations: Observations, Theory and Simulations

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    We review observations and gravitational lensing theory related to the magnification of background QSOs by intervening overdensities, and the induced cross-correlation between sources and foreground galaxies. We pay special attention to simulations, and present some preliminary results from high resolution cluster simulations, which show the role of the halo core and substructure on non-linear magnification. For massive clusters, deviations from the weak gravitational lensing regime are significant on arcmin scales and bellow. The accumulated knowledge in the field already shows that gravitational lensing magnification is an important astrophysical and cosmological tool.Comment: 6 pages. Presented at "100 years of relativity -- international conference on classical and quantum aspects of gravity and cosmology", 200

    Multiparametric magnetic resonance imaging of the prostate-a basic tutorial.

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    Prostate cancer is the second most common cause of cancer related death in the United States and the most commonly diagnosed malignancy in men. In general, prostate cancer is slow growing, though there is a broad spectrum of disease that may be indolent, or aggressive and rapidly progressive. Screening for prostate is controversial and complicated by lack of specificity and over diagnosis of clinically insignificant cancer. Imaging has played a role in diagnosis of prostate cancer, primarily through systemic transrectal ultrasound (TRUS) guided biopsy. While TRUS guided biopsy radically changed prostate cancer diagnosis, it still remains limited by low resolution, poor tissue characterization, relatively low sensitivity and positive predictive value. Advances in multiparametric magnetic resonance imaging (mpMRI) have allowed more accurate detection, localization, and staging as well as aiding in the role of active surveillance (AS). The use of mpMRI for the evaluation of prostate cancer has increased dramatically and this trend is likely to continue as the technique is rapidly improving and its applications expand. The purpose of this article is to review the basic principles of mpMRI of the prostate and its clinical applications, which will be reviewed in greater detail in subsequent chapters of this issue

    SZ scaling relations in Galaxy Clusters: results from hydrodynamical N-body simulations

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    Observations with the SZ effect constitute a powerful new tool for investigating clusters and constraining cosmological parameters. Of particular interest is to investigate how the SZ signal correlates with other cluster properties, such as the mass, temperature and X-ray luminosities. In this presentation we quantify these relations for clusters found in hydrodynamical simulations of large scale structure and investigate their dependence on the effects of radiative cooling and pre-heating.Comment: 10 pages, 3 figures, LaTeX. To appear in proceedings of the JENAM 2002 conference. For a more detailed analysis see astro-ph/0308074, whose simulations supersede those presented at this conferenc
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