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BACKGROUND Severe acute respiratory syndrome (SARS) is a condition of unknown cause that has recently been recognized in patients in Asia, North America, and Europe. This report summarizes the initial epidemiologic findings, clinical description, and diagnostic findings that followed the identification of SARS in Canada. METHODS SARS was first identified(More)
Size distributions of non-volatile particle residuals (Dp<800 nm) at a rural site in Germany and relation to air mass origin C. Engler, D. Rose, B. Wehner, A. Wiedensohler, E. Brüggemann, T. Gnauk, G. Spindler, T. Tuch, and W. Birmili Leibniz Institute for Tropospheric Research, Leipzig, Germany UFZ Center for Environmental Research, Department of Human(More)
To determine factors that predispose or protect healthcare workers from severe acute respiratory syndrome (SARS), we conducted a retrospective cohort study among 43 nurses who worked in two Toronto critical care units with SARS patients. Eight of 32 nurses who entered a SARS patient's room were infected. The probability of SARS infection was 6% per shift(More)
Atmospheric aerosol particles serving as cloud condensation nuclei (CCN) are key elements of the hydrological cycle and climate. We have measured and characterized CCN at water vapor supersaturations in the range of S=0.10–0.82% in pristine tropical rainforest air during the AMAZE-08 campaign in central Amazonia. The effective hygroscopicity parameters(More)
Performance of a wide range of simple visual tasks improves with practice. Here we ask whether such learning occurs for the fundamental visual task of luminance contrast detection. In two experiments we find that contrast sensitivity increases following extensive practice at detecting briefly presented sinusoidal luminance gratings and that learning is(More)
Over the 1980s and 1990s, monetary policy in most industrialized countries has focussed increasingly on achieving rates of inflation at or close to price stability. The result in the 1990s has been a remarkable convergence in these economies towards relatively low rates of inflation. In some countries, such as New Zealand, Canada, the United Kingdom, and(More)
CONTEXT Severe acute respiratory syndrome (SARS) is an emerging infectious disease that first manifested in humans in China in November 2002 and has subsequently spread worldwide. OBJECTIVES To describe the clinical characteristics and short-term outcomes of SARS in the first large group of patients in North America; to describe how these patients were(More)
Recent developments in the efficient estimation of threshold are here extended to the problem of how best to estimate the slope of the psychometric function. An adaptive method is described for selecting stimulus intensities that are optimal for slope estimation. A two-dimensional array of probabilities of different thresholds and slopes is used to(More)