Excursions into the Evolution of Early-Type Galaxies in Clusters

Recent observations have revealed that early-type galaxies (ETG) in clusters comprise an old galaxy population that is evolving passively. We review some recent observations from the ground and from HST that show that ETG have undergone a significant amount of luminosity evolution. This evolution is traced by two projections of the fundamental plane (FP): the size-magnitude relation (SMR) and the color-magnitude relation (CMR). We will briefly discuss the relevance of all these results in the context of the universality of the IMF.Comment: 10 pages, 2 figures, to appear in the proccedings of "New Quests in Stellar Astrophysics: The Link Between Stars and Cosmology, Chavez et al. ed

Manifestations of a Massive Black Hole in the Galactic Center

A young star cluster is a less contrived explanation than a massive black hole for many of the features seen in the Galactic center. However from a Copernican point of view, this explanation is less attractive than a black hole. The evidence for a ~ 10^6 M_⊙ black hole is becoming progressively less convincing, but the case against it is no stronger. We describe the development of a singular star cluster, as well as the processes of stellar disruption, merging, and gas accretion in such a cluster. Recently merged stars and tidally stripped giants may be detectable within an arcminute of the Galactic Center. We examine the physics of star formation in the inner parsecs of the galaxy, and the problem of maintaining the two parsec molecular torus

Transcribing oral discourse: A survey and a model system

Researchers who study discourse must frequently transcribe a variety of paralinguistic dimensions to document the ways in which utterances are spoken. However, there are a large number of such underlying dimensions, and researchers have developed different transcription systems to describe them. The purpose of this article is to offer a model transcription system, based on a 5-year survey of the systems employed in articles appearing in Discourse Processes. A relatively small number of dimensions can account for most of the phenomena that have been of interest to discourse researchers. The proposed system, which is based on a set of 7 design principles, is offered as a model for use in research and publication. Copyright © 2000, Lawrence Erlbaum Associates, Inc

Mathematical Solution of the Problem of Roll Waves in Inclined Open Channels

the nondimensional wavespeed as a function of the rotational Froude number. For the same Froude number, the rotational wavespeed is slightly greater than the equivalent inclined film wavespeed. A stability condition for wave motion has also been obtained. The stability condition indicates that the critical Froude number for rotating films is larger than that for inclined films