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SUNSHINE, EARTHSHINE AND CLIMATE CHANGE: II. SOLAR ORIGINS OF VARIATIONS IN THE EARTH'S ALBEDO
GOODE P. R.,PALLE E.,YURCHYSHYN V.,QIU J.,HICKEY J.,RODRIGUEZ P. MONTANES,CHU M.-C.,KOLBE E.,BROWN C.T.,KOONIN S.E. The Korean Astronomical Society 2003 Journal of The Korean Astronomical Society Vol.36 No.suppl1
There are terrestrial signatures of the solar activity cycle in ice core data (Ram & Stoltz 1999), but the variations in the sun's irradiance over the cycle seem too small to account for the signature (Lean 1997; Goode & Dziembowski 2003). Thus, one would expect that the signature must arise from an indirect effect(s) of solar activity. Such an indirect effect would be expected to manifest itself in the earth's reflectance. Further, the earth's climate depends directly on the albedo. Continuous observations of the earthshine have been carried out from Big Bear Solar Observatory since December 1998, with some more sporadic measurements made during the years 1994 and 1995. We have determined the annual albedos both from our observations and from simulations utilizing the Earth Radiation Budget Experiment (ERBE) scene model and various datasets for the cloud cover, as well as snow and ice cover. With these, we look for inter-annual and longer-term changes in the earth's total reflectance, or Bond albedo. We find that both our observations and simulations indicate that the albedo was significantly higher during 1994-1995 (activity minimum) than for the more recent period covering 1999-2001 (activity maximum). However, the sizes of the changes seem somewhat discrepant. Possible indirect solar influences on the earth's Bond albedo are discussed to emphasize that our earthshine data are already sufficiently precise to detect, if they occur, any meaningful changes in the earth's reflectance. Still greater precision will occur as we expand our single site observations to a global network.
Giant viruses with an expanded complement of translation system components
Schulz, Frederik,Yutin, Natalya,Ivanova, Natalia N.,Ortega, Davi R.,Lee, Tae Kwon,Vierheilig, Julia,Daims, Holger,Horn, Matthias,Wagner, Michael,Jensen, Grant J.,Kyrpides, Nikos C.,Koonin, Eugene V.,W American Association for the Advancement of Scienc 2017 Science Vol.356 No.6333
<P>The discovery of giant viruses blurred the sharp division between viruses and cellular life. Giant virus genomes encode proteins considered as signatures of cellular organisms, particularly translation system components, prompting hypotheses that these viruses derived from a fourth domain of cellular life. Here we report the discovery of a group of giant viruses (Klosneuviruses) in metagenomic data. Compared with other giant viruses, the Klosneuviruses encode an expanded translation machinery, including aminoacyl transfer RNA synthetases with specificities for all 20 amino acids. Notwithstanding the prevalence of translation system components, comprehensive phylogenomic analysis of these genes indicates that Klosneuviruses did not evolve from a cellular ancestor but rather are derived from a much smaller virus through extensive gain of host genes.</P>