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Institution

University of Arizona

EducationTucson, Arizona, United States
About: University of Arizona is a education organization based out in Tucson, Arizona, United States. It is known for research contribution in the topics: Population & Galaxy. The organization has 63805 authors who have published 155998 publications receiving 6854915 citations. The organization is also known as: UA & U of A.
Topics: Population, Galaxy, Star formation, Redshift, Planet


Papers
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Journal ArticleDOI
TL;DR: Hepatitis B e antigen and hepatitis B viral DNA disappeared from serum significantly more often in the patients given prednisone plus interferon or 5 million units of interferons alone than in the untreated controls.
Abstract: Background and Methods. Chronic hepatitis B is a common and often progressive liver disorder for which there is no accepted therapy. To assess the efficacy of treatment with interferon, we randomly assigned patients with chronic hepatitis B to one of the following regimens: prednisone for 6 weeks followed by 5 million units of recombinant interferon alfa-2b daily for 16 weeks; placebo followed by 5 million units of interferon daily for 16 weeks; placebo followed by 1 million units of interferon daily for 16 weeks; or observation with no treatment. Results. Hepatitis B e antigen and hepatitis B viral DNA disappeared from serum significantly more often in the patients given prednisone plus interferon (16 of 44 patients, or 36 percent) or 5 million units of interferon alone (15 of 41; 37 percent) than in the untreated controls (3 of 43; 7 percent; P<0.001); the difference between those given 1 million units of interferon (7 of 41; 17 percent) and the controls was not significant. The strongest indep...

779 citations

Journal ArticleDOI
TL;DR: The close relationship between P and RNA contents indicates that ribosomes themselves represent a biogeochemically significant repository of P in ecosystems and that allocation of P to ribosome generation is a central process in biological production in ecological systems.
Abstract: Biological stoichiometry provides a mechanistic theory linking cellular and biochemical features of co-evolving biota with constraints imposed by ecosystem energy and nutrient inputs. Thus, understanding variation in biomass carbon : nitrogen : phosphorus (C : N : P) stoichiometry is a major priority for integrative biology. Among various factors affecting organism stoichiometry, differences in C : P and N : P stoichiometry have been hypothesized to reflect organismal P-content because of altered allocation to P-rich ribosomal RNA at different growth rates (the growth rate hypothesis, GRH). We tested the GRH using data for microbes, insects, and crustaceans and we show here that growth, RNA content, and biomass P content are tightly coupled across species, during ontogeny, and under physiological P limitation. We also show, however, that this coupling is relaxed when P is not limiting for growth. The close relationship between P and RNA contents indicates that ribosomes themselves represent a biogeochemically significant repository of P in ecosystems and that allocation of P to ribosome generation is a central process in biological production in ecological systems.

779 citations

Journal ArticleDOI
TL;DR: In this paper, the authors discuss new constraints on the epoch of cosmic reionization and test the assumption that most of the ionizing photons responsible arose from high-redshift star-forming galaxies.
Abstract: We discuss new constraints on the epoch of cosmic reionization and test the assumption that most of the ionizing photons responsible arose from high-redshift star-forming galaxies. Good progress has been made in charting the end of reionization through spectroscopic studies of z≃ 6–8 QSOs, gamma-ray bursts, and galaxies expected to host Lyα emission. However, the most stringent constraints on its duration have come from the integrated optical depth, τ, of Thomson scattering to the cosmic microwave background. Using the latest data on the abundance and luminosity distribution of distant galaxies from Hubble Space Telescope imaging, we simultaneously match the reduced value τ = 0.066 ± 0.012 recently reported by the Planck collaboration and the evolving neutrality of the intergalactic medium with a reionization history within 6 ≾ z ≾ 10, thereby reducing the requirement for a significant population of very high redshift (z ≫ 10) galaxies. Our analysis strengthens the conclusion that star-forming galaxies dominated the reionization process and has important implications for upcoming 21 cm experiments and searches for early galaxies with the James Webb Space Telescope.

779 citations

Book ChapterDOI
21 Jun 2005

778 citations


Authors

Showing all 64388 results

NameH-indexPapersCitations
Simon D. M. White189795231645
Julie E. Buring186950132967
David H. Weinberg183700171424
Richard Peto183683231434
Xiaohui Fan183878168522
Dennis S. Charney179802122408
Daniel J. Eisenstein179672151720
David Haussler172488224960
Carlos S. Frenk165799140345
Jian-Kang Zhu161550105551
Tobin J. Marks1591621111604
Todd Adams1541866143110
Jane A. Cauley15191499933
Wei Zheng1511929120209
Daniel L. Schacter14959290148
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Performance
Metrics
No. of papers from the Institution in previous years
YearPapers
2023205
2022987
20217,005
20207,325
20196,716
20186,375