3,031 research outputs found
Comparing Caddo and Coles Creek Pottery Using Petrographic Analysis
Pottery classified as “Coles Creek Incised” is common both to the earliest Caddo sites along the Red River and to contemporary sites in the Lower Mississippi Valley. Although it often is suggested that Coles Creek pottery from the two regions can be distinguished by differences in paste, no detailed comparative studies have been carried out. An initial attempt to identify variation through the use of petrographic analysis was carried out by comparing 50 samples drawn from sites in northwest and central Louisiana. Although no sharp dichotomy was noted between the regions, the study identified distinctions that support the notion that most Coles Creek pottery was made locally and different technological traditions may be represented
Galactic Winds
Galactic winds are the primary mechanism by which energy and metals are
recycled in galaxies and are deposited into the intergalactic medium. New
observations are revealing the ubiquity of this process, particularly at high
redshift. We describe the physics behind these winds, discuss the observational
evidence for them in nearby star-forming and active galaxies and in the
high-redshift universe, and consider the implications of energetic winds for
the formation and evolution of galaxies and the intergalactic medium. To
inspire future research, we conclude with a set of observational and
theoretical challenges.Comment: Paper to be published in 2005 Annual Review of Astronomy &
Astrophysics; revision based on comments from readers and production editor.
Figure 1 was replaced to show the proper density scale. A PDF file combining
both text and figures is available at
http://www.astro.umd.edu/~veilleux/pubs/araa.pd
Assessing Causation in Breast Implant Litigation: The Role of Science Panels
In two recent cases, federal judges appointed panels of scientific experts to help assess conflicting scientific testimony regarding causation of systemic injuries by silicone gel breast implants. This article will describe the circumstances that gave rise to the appointments, the procedures followed in making the appointments and reporting to the courts, and the reactions of the participants in the proceedings
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