Kepler-16: a transiting circumbinary planet     

Doyle LR  Carter JA  Fabrycky DC  Slawson RW  Howell SB  Winn JN  Orosz JA  Prša A  Welsh WF  Quinn SN  Latham D  Torres G  Buchhave LA  Marcy GW  Fortney JJ  Shporer A  Ford EB  Lissauer JJ  Ragozzine D  Rucker M  Batalha N  Jenkins JM  Borucki WJ  Koch D  Middour CK  Hall JR  McCauliff S  Fanelli MN  Quintana EV  Holman MJ  Caldwell DA  Still M  Stefanik RP  Brown WR  Esquerdo GA  Tang S  Furesz G  Geary JC  Berlind P  Calkins ML  Short DR  Steffen JH  Sasselov D  Dunham EW  Cochran WD  Boss A  Haas MR  Buzasi D  Fischer D 《Science (New York, N.Y.)》2011,333(6049):1602-1606

We report the detection of a planet whose orbit surrounds a pair of low-mass stars. Data from the Kepler spacecraft reveal transits of the planet across both stars, in addition to the mutual eclipses of the stars, giving precise constraints on the absolute dimensions of all three bodies. The planet is comparable to Saturn in mass and size and is on a nearly circular 229-day orbit around its two parent stars. The eclipsing stars are 20 and 69% as massive as the Sun and have an eccentric 41-day orbit. The motions of all three bodies are confined to within 0.5° of a single plane, suggesting that the planet formed within a circumbinary disk.  相似文献   

Whole-genome shotgun sequencing of mitochondria from ancient hair shafts     

Gilbert MT  Tomsho LP  Rendulic S  Packard M  Drautz DI  Sher A  Tikhonov A  Dalén L  Kuznetsova T  Kosintsev P  Campos PF  Higham T  Collins MJ  Wilson AS  Shidlovskiy F  Buigues B  Ericson PG  Germonpré M  Götherström A  Iacumin P  Nikolaev V  Nowak-Kemp M  Willerslev E  Knight JR  Irzyk GP  Perbost CS  Fredrikson KM  Harkins TT  Sheridan S  Miller W  Schuster SC 《Science (New York, N.Y.)》2007,317(5846):1927-1930

Although the application of sequencing-by-synthesis techniques to DNA extracted from bones has revolutionized the study of ancient DNA, it has been plagued by large fractions of contaminating environmental DNA. The genetic analyses of hair shafts could be a solution: We present 10 previously unexamined Siberian mammoth (Mammuthus primigenius) mitochondrial genomes, sequenced with up to 48-fold coverage. The observed levels of damage-derived sequencing errors were lower than those observed in previously published frozen bone samples, even though one of the specimens was >50,000 14C years old and another had been stored for 200 years at room temperature. The method therefore sets the stage for molecular-genetic analysis of museum collections.  相似文献   

EDWIN E. HOWELL     

Gilbert GK 《Science (New York, N.Y.)》1911,33(854):720-721

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STYLE IN SCIENTIFIC COMPOSITION     

Gilbert GK 《Science (New York, N.Y.)》1905,21(523):28-29

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THE NATURALIST'S UNIVERSAL DIRECTORY     

Gilbert GK 《Science (New York, N.Y.)》1905,21(536):548-549

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SIMPLIFIED SPELLING     

Gilbert GK 《Science (New York, N.Y.)》1897,5(109):185-186

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Pre-Bonneville climate     

Gilbert NG 《Science (New York, N.Y.)》1883,2(27):170

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Water transfer from agriculture to urban uses: lessons learned, with policy considerations   总被引：1，自引：0，他引：1  

Gilbert Levine  Randolph Barker  Cheng Chang Huang 《Paddy and Water Environment》2007,5(4):213-222

This paper sets forth the accomplishments to date of the international collaborative study program on efficient and equitable transfer of water from agriculture to other uses. The research consists of several components. First a bibliographical review was prepared of literature available on the practice of inter-sector water transfer. Second, nine case studies have been prepared that illustrate inter-sector water transfer under a variety of physical and economic and political environments. Third, a framework has been developed for characterizing and comparing water transfer options and compensation among case studies. We discuss the pricing of irrigation water in determining compensation. We develop a decision tree that traces the paths to the various sector water transfer options. Finally, we discuss water transfer policy options with specific reference to Taiwan, though they have more general relevance. Three options are identified which reflect different objectives for government intervention.  相似文献   

Rice-related greenhouse gases in Japan, variations in scale and time and significance for the Kyoto Protocol     

Meinhard Breiling  Shizuka Hashimoto  Yohei Sato  Gilbert Ahamer 《Paddy and Water Environment》2005,3(1):39-46

The contribution of rice production to the three major greenhouse gases CO₂, CH₄ and N₂O in 1990, the base year of the Kyoto protocol is investigated for Japan. For the CO₂ assessment, we use a top-down life cycle approach, CH₄ is assessed using the Japanese GHG emission inventory and N₂O is assessed according to the ratio of rice area divided by the total area of agricultural soils. In total, 1.6% of greenhouse gas (GHG) emissions in 1990 originated from rice production. Next, we assess regional variations in nine rice-producing regions, based on the CO₂ data of 1990. General trends in rice production from 1960 to 2000 and data from the Japanese GHG emission inventory since 1990 are used to assess variations in time. The rice-related GHG emissions decreased to 1.05% of the total GHG emissions in 2001 and will be less than half the 1990 level in 2012, mainly due to the decrease in rice production. Contrary to the trend in GHG emissions of rice, overall GHG emissions increased as rice production fulfils important roles, in mitigating global warming and in adapting to changing climates. The protection of rice production is required to counter the increase of GHG emissions in transportation, waste and domestic sectors and to minimize problems related to landscape, water and natural hazard management.  相似文献   

Changes in free amino acid and sugar levels of dried figs during aflatoxin B1 production by Aspergillus flavus and Aspergillus parasiticus     

Senyuva HZ  Gilbert J  Oztürkoglu S  Ozcan S  Gürel N 《Journal of agricultural and food chemistry》2008,56(20):9661-9666

An aqueous slurry of gamma-irradiated sterilized dried figs was inoculated with toxigenic strains of Aspergillus flavus and Aspergillus parasiticus. During incubation at 28 degrees C, pH, fructose, glucose, and free amino acids were determined by high-performance liquid chromatography and liquid chromatography (LC)/mass spectrometry, respectively, over 13 time points (1-20 days). At the same 13 time points using a LC/time-of-flight mass spectrometry screening method, aflatoxin B 1 and other secondary metabolites were simultaneously monitored. During the course of incubation, the pH significantly decreased and aflatoxin B 1 formation correlated with a reduction in proline content for both fungi. Of the 22 free amino acids that were monitored, only proline and cystine were found to be critical in supporting aflatoxin production. Levels of fructose and glucose steadily declined during incubation, until glucose was almost exhausted after 21 days. These time-course experiments confirmed the need for carbon and nitrogen sources for aflatoxin production in dried figs, and the favorable composition of figs as a fungal growth medium.  相似文献