69 research outputs found
Copernicus's Development in Context:Politics, Astrology, Cosmology and a Prince-Bishopric
ArgumentDuring the two decades before the turning point in Copernicus's personal and scientific development in 1510, he had experience of political activity which has been largely ignored by the existing Copernicus literature but part of which is reconstructed in outline in this paper. Given the close linkage between politics and astrology, Copernicus's likely reaction to astrology is re-examined here. This reconstruction also suggests that the turning point in 1510, when Copernicus left his post as secretary to his uncle Lucas Watzenrode the prince-bishop of Warmia, was not only linked to Copernicus's first version of his heliocentric theory in theCommentariolus, but also to major political setbacks being experienced by Watzenrode during these years, and with the publication of Copernicus's translation of theLettersof Theophylactus Simocatta. Some of these considerations contribute to maintaining the view that Copernicus and his work were in several respects exceptional.</jats:p
Do Gamma-Ray Burst Sources Repeat?
The demonstration of repeated gamma-ray bursts from an individual source
would severely constrain burst source models. Recent reports (Quashnock and
Lamb 1993; Wang and Lingenfelter 1993) of evidence for repetition in the first
BATSE burst catalog have generated renewed interest in this issue. Here, we
analyze the angular distribution of 585 bursts of the second BATSE catalog
(Meegan et al. 1994). We search for evidence of burst recurrence using the
nearest and farthest neighbor statistic and the two-point angular correlation
function. We find the data to be consistent with the hypothesis that burst
sources do not repeat; however, a repeater fraction of up to about 20% of the
observed bursts cannot be excluded.Comment: ApJ Letters, in press, 13 pages, including three embedded figures.
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Identifying Patients at High Risk of a Cardiovascular Event in the Near Future Current Status and Future Directions: Report of a National Heart, Lung, and Blood Institute Working Group
The National Heart, Lung, and Blood Institute convened a working group to provide basic and clinical research recommendations to the National Heart, Lung, and Blood Institute on the development of an integrated approach for identifying those individuals who are at high risk for a cardiovascular event such as acute coronary syndromes (ACS) or sudden cardiac death in the ânear term.â The working group members defined near-term as occurring within 1 year of the time of assessment. The participants reviewed current clinical cardiology practices for risk assessment and state-of-the-science techniques in several areas, including biomarkers, proteomics, genetics, psychosocial factors, imaging, coagulation, and vascular and myocardial susceptibility. This report presents highlights of these reviews and a summary of suggested research directions
Perspectives on Risk Perceptions
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/72341/1/j.1539-6924.1981.tb01409.x.pd
A nomenclature for restriction enzymes, DNA methyltransferases, homing endonucleases and their genes
A nomenclature is described for restriction endonucleases, DNA methyltransferases, homing endonucleases and related genes and gene products. It provides explicit categories for the many different Type II enzymes now identified and provides a system for naming the putative genes found by sequence analysis of microbial genome
Micromechanical Properties of Injection-Molded StarchâWood Particle Composites
The micromechanical properties of injection molded starchâwood particle composites were investigated as a function of particle content and humidity conditions.
The composite materials were characterized by scanning electron microscopy and X-ray diffraction methods. The microhardness
of the composites was shown to increase notably with the concentration of the wood particles. In addition,creep behavior under the indenter and temperature dependence
were evaluated in terms of the independent contribution of the starch matrix and the wood microparticles to the hardness value. The influence of drying time on the density
and weight uptake of the injection-molded composites was highlighted. The results revealed the role of the mechanism of water evaporation, showing that the dependence of water uptake and temperature was greater for the starchâwood composites than for the pure starch sample. Experiments performed during the drying process at 70°C indicated that
the wood in the starch composites did not prevent water loss from the samples.Peer reviewe
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