2,312 research outputs found
Triterpenoids
This review covers the isolation and structure determination of triterpenoids reported during 2012 including squalene derivatives, lanostanes, holostanes, cycloartanes, cucurbitanes, dammaranes, euphanes, tirucallanes, tetranortriterpenoids, quassinoids, lupanes, oleananes, friedelanes, ursanes, hopanes, serratanes, isomalabaricanes and saponins; 348 references are cited
Towards More Precise Photometric Redshifts: Calibration Via CCD Photometry
We present the initial results from a deep, multi-band photometric survey of
selected high Galactic latitude redshift fields. Previous work using the
photographic data of Koo and Kron demonstrated that the distribution of
galaxies in the multi-dimensional flux space U B R I is nearly planar. The
position of a galaxy within this plane is determined by its redshift,
luminosity and spectral type. Using recently acquired deep CCD photometry in
existing, published redshift fields, we have redetermined the distribution of
galaxies in this four-dimensional magnitude space. Furthermore, from our CCD
photometry and the published redshifts, we have quantified the
photometric-redshift relation within the standard AB magnitude system. This
empirical relation has a measured dispersion of approximately 0.02 for z < 0.4.
With this work we are reaching the asymptotic intrinsic dispersions that were
predicted from simulated distributions of galaxy colors.Comment: submitted to the Astrophysical Journal Letter
Evidence on the Economics of Equity Return Volatility Clustering
The underlying economic sources of volatility clustering in asset returns remain a puzzle in financial economics. Using daily equity returns, we study variation in the volatility relation between the conditional variance of individual firm returns and yesterday's market return shock. We find a number of regularities in this market-to-firm volatility relation. (1) It decreases following macroeconomic news announcements; (2) it does not change systematically during the high-news months when firms announce quarterly earnings; and (3) it increases substantially with our measures of dispersion-in-beliefs across traders about the market's common-factor signal. Our evidence suggests that volatility-clustering is a natural result of a price formation process with heterogeneous beliefs across traders, and that volatility clustering is not attributable to an autocorrelated news-generation process around public information such as macroeconomic news releases or firms' earnings releases. We find consistent results in our sample of large-capitalization firms in Japan and the U.K., which suggests a generality of our results and bolsters our economic interpretation.
Co-Creation as a Twenty-First Century Archaeology Museum
This article evaluates how the C. H. Nash Museum at Chucalissa has attempted to overcome various obstacles in the last decade; most notably proper curation as well as becoming a modern viable and socially relevant institution in the face of various issues like understaffing
Evolution in the Clustering of Galaxies for Z < 1
Measuring the evolution in the clustering of galaxies over a large redshift
range is a challenging problem. For a two-dimensional galaxy catalog, however,
we can measure the galaxy-galaxy angular correlation function which provides
information on the density distribution of galaxies. By utilizing photometric
redshifts, we can measure the angular correlation function in redshift shells
(Brunner 1997, Connolly et al. 1998) which minimizes the galaxy projection
effect, and allows for a measurement of the evolution in the correlation
strength with redshift. In this proceedings, we present some preliminary
results which extend our previous work using more accurate photometric
redshifts, and also incorporate absolute magnitudes, so that we can measure the
evolution of clustering with either redshift or intrinsic luminosity.Comment: 6 pages, 6 figures requires paspconf.sty. To be published in
"Photometric Redshifts and High Redshift Galaxies", eds. R. Weymann, L.
Storrie-Lombardi, M. Sawicki & R. Brunner, (San Francisco: ASP Conference
Series
A Consumer Test of Citrus Drinks made from Comminuted Whole Citrus Fruit
Consumer, Citrus, Whole Citrus Fruit, Citrus Fruit, Consumer Test, Consumer/Household Economics, Food Consumption/Nutrition/Food Safety,
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