6,396 research outputs found
The Millennium Galaxy Catalogue: The nearby supermassive black hole mass function
We highlight the correlation between a galaxy's supermassive black hole mass
and the Sersic-index of the host spheroid or bulge component. From our
bulge-disk decompositions of 10 095 galaxies, drawn from the Millennium Galaxy
Catalogue, we construct the local (z < 0.18) mass function of supermassive
black holes. We compare our results to those of McLure & Dunlop (2004) and
conclude that the mass density of supermassive black holes may be marginally
higher than previously supposed. This increase is predominantly due to the
inclusion of low mass and later-type bulges. More details will be presented in
a forthcoming paper.Comment: Contributed article to the Fabulous Destiny of Galaxies meetin
Generalized Dissociating Gas Flow
A generalized approach to the one-dimensional flow of a dissociated gas is presented. The flow is characterized by the flow parameters F, G, H, and I, and the degree of dissociation, which are defined. The equation of state and the equations for the dynamic and thermodynamic properties of the gas are presented for the dissociating gas. Equations are presented which give the aerothermodynamic flow properties as a function of the degree of dissociation, the frozen flow Mach number MF, and the initial values of G, H, and I for any arbitrary given flight condition. These equations are solved for the limiting subsonic and hypersonic solutions for the flow variables as the frozen flow Mach number MF tends towards zero and infinity, respectively. Several aspects of the physical significance of these results are discussed from the point of view of atmospheric planetary entry of an aerospace vehicle. The generalized nondimensional flow function F is defined in terms of the flow parameters G, H, and I , and is also given as a function of MF, H, and a, in general. This functional relationship is displayed in graphical form which is useful for determining various aspects of the resulting flow, and providing further insight into the flow process under consideration. Specifically, several flow regimes are delineated
Consistency conditions for regulatory analysis of financial institutions: a comparison of frontier efficiency methods
We propose a set of consistency conditions that frontier efficiency measures should meet to be most useful for regulatory analysis or other purposes. The efficiency estimates should be consistent in their efficiency levels, rankings, and identification of best and worst firms, consistent over time and with competitive conditions in the market, and consistent with standard nonfrontier measures of performance. We provide evidence on these conditions by evaluating and comparing efficiency estimates on U.S. bank efficiency from variants of all four of the major approaches -- DEA, SFA, TFA, and DFA -- and find mixed results.Financial institutions ; Bank supervision
Book Reviews
Book Reviews --
The John Randolph Tucker Lectures--1953-1956 Lexington, Virginia School of Law, Washington and Lee University, 1957. Pp. 208.
reviewer: Paul Carrington
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Desegregation and the Law By Albert P. Blaustein and Clarence Clyde Ferguson, Jr. New Brunswick: Rutgers University Press,1957. Pp. xiv, 332.
reviewer: J. Allen Smith
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The Federal Tort Claims Act By William B. Wright Forward by Emile Z. Berman New York: Central Book Co., 1957. Pp. 248.
reviewer: Stanley D. Ros
Role of Ryanodine Receptors in the Assembly of Calcium Release Units in Skeletal Muscle
Abstract. In muscle cells, excitationâcontraction (eâc) coupling is mediated by âcalcium release units,â junctions between the sarcoplasmic reticulum (SR) and exterior membranes. Two proteins, which face each other, are known to functionally interact in those structures: the ryanodine receptors (RyRs), or SR calcium release channels, and the dihydropyridine receptors (DHPRs), or L-type calcium channels of exterior membranes. In skeletal muscle, DHPRs form tetrads, groups of four receptors, and tetrads are organized in arrays that face arrays of feet (or RyRs). Triadin is a protein of the SR located at the SRâexterior membrane junctions, whose role is not known. We have structurally characterized calcium release units in a skeletal muscle cell line (1B5) lacking Ry1R. Using immunohistochemistry and freeze-fracture electron microscopy, we find that DHPR and triadin are clustered in foci in differentiating 1B5 cells. Thin section electron microscopy reveals numerous SRâexterior membrane junctions lacking foot structures (dyspedic). These results suggest that components other than Ry1Rs are responsible for targeting DHPRs and triadin to junctional regions. However, DHPRs in 1B5 cells are not grouped into tetrads as in normal skeletal muscle cells suggesting that anchoring to Ry1Rs is necessary for positioning DHPRs into ordered arrays of tetrads. This hypothesis is confirmed by finding a ârestoration of tetradsâ in junctional domains of surface membranes after transfection of 1B5 cells with cDNA encoding for Ry1R
Analytic Results for the Gravitational Radiation from a Class of Cosmic String Loops
Cosmic string loops are defined by a pair of periodic functions and
, which trace out unit-length closed curves in three-dimensional
space. We consider a particular class of loops, for which lies along
a line and lies in the plane orthogonal to that line. For this class
of cosmic string loops one may give a simple analytic expression for the power
radiated in gravitational waves. We evaluate exactly in
closed form for several special cases: (1) a circle traversed
times; (2) a regular polygon with sides and interior vertex angle
; (3) an isosceles triangle with semi-angle .
We prove that case (1) with is the absolute minimum of within
our special class of loops, and identify all the stationary points of
in this class.Comment: 15 pages, RevTex 3.0, 7 figures available via anonymous ftp from
directory pub/pcasper at alpha1.csd.uwm.edu, WISC-MILW-94-TH-1
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