128 research outputs found
The Distribution of Dust and Gas in Elliptical Galaxies
Results from IRAS and recent optical CCD surveys are examined to discuss the
distribution and origin of dust and ionized gas in elliptical galaxies. In
strong contrast with the situation among spiral galaxies, masses of dust in
elliptical galaxies as derived from optical extinction are an order of
magnitude LOWER than those derived from IRAS data. I find that this dilemma can
be resolved by assuming the presence of a diffusely distributed component of
dust which is not detectable in optical data.
The morphology of dust lanes and their association with ionized gas in
elliptical galaxies argues for an external origin of BOTH components of the
ISM.Comment: Invited talk given at conference on "NEW EXTRAGALACTIC PERSPECTIVES
IN THE NEW SOUTH AFRICA: Changing Perceptions of the Morphology, Dust Content
and Dust-Gas Ratios in Galaxies", Held in Johannesburg, South Africa, during
January 22-26, 1996. Proceedings will be edited by D.L. Block and published
by Kluwer, Dordrecht, The Netherlands. uuencoded, gzipped LaTeX file of 8
pages; figures included as PostScript files (enclosed). Uses crckapb.sty
(enclosed) and psfig.st
Inhibition of CD203c membrane up-regulation in human basophils by high dilutions of histamine: a controlled replication study
none5noPrevious research suggests that human basophil activation may be inhibited by histamine even at extremely low doses (high dilutions).
In our experiment, membrane up-regulation of CD203c, which proved to be a more consistent activation marker than CD63, was significantly inhibited in samples treated with histamine at the dilutions of 2C, 12C, 14C, 15C and 16C. Control water dilutions/succussions did not show any significant effect. Therefore, using a strictly standardized flow cytometry protocol and a new dilution/succussion procedure, we have shown that low and high dilution of histamine do inhibit CD203c up-regulation in anti-IgE stimulated basophils.mixedS. Chirumbolo; M. Brizzi; R. Ortolani; A. Vella; P. BellaviteS. Chirumbolo; M. Brizzi; R. Ortolani; A. Vella; P. Bellavit
Computational and mathematical approaches to societal transitions
After an introduction of the theoretical framework and concepts of transition studies, this article gives an overview of how structural change in social systems has been studied from various disciplinary perspectives. This overview first leads to the conclusion that computational and mathematical approaches and their practical form, modeling, up till now, have been almost absent in the research and theorizing of structural change or transitions in social systems. Second, this review of the social science literature suggests numerous theoretical constructs relevant for transition modeling. Relevant concepts include the conceptualization of the micro-to-macro link, the importance of explaining both stability and change, quantitative and qualitative definitions of structural change, the use of dichotomies, synchronic and diachronic reasoning in explaining structural change, definitions of basic patterns of social change, the conceptualization of resistance to change and intentional and normative aspects of social change. This article employs these theoretical concepts to describe and discuss the models presented in this special issue in order to develop an understanding of what exactly entails a computational or mathematical approach to societal transitions
Centrality and transverse momentum dependence of D-0-meson production at mid-rapidity in Au plus Au collisions ats root S-NN=200 GeV
Collision-energy dependence of p(t) correlations in Au plus Au collisions at energies available at the BNL Relativistic Heavy Ion Collider
Measurement of the H-3(Lambda) lifetime in Au plus Au collisions at the BNL Relativistic Heavy Ion Collider
Clinical relevance of contextual factors as triggers of placebo and nocebo effects in musculoskeletal pain
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