Independent variations of CH₄ emissions and isotopic composition over the past 160,000 years

During the last glacial cycle, greenhouse gas concentrations fluctuated on decadal and longer timescales. Concentrations of methane, as measured in polar ice cores, show a close connection with Northern Hemisphere temperature variability, but the contribution of the various methane sources and sinks to changes in concentration is still a matter of debate. Here we assess changes in methane cycling over the past 160,000 years by measurements of the carbon isotopic composition delta C-13 of methane in Antarctic ice cores from Dronning Maud Land and Vostok. We find that variations in the delta C-13 of methane are not generally correlated with changes in atmospheric methane concentration, but instead more closely correlated to atmospheric CO2 concentrations. We interpret this to reflect a climatic and CO2-related control on the isotopic signature of methane source material, such as ecosystem shifts in the seasonally inundated tropical wetlands that produce methane. In contrast, relatively stable delta C-13 values occurred during intervals of large changes in the atmospheric loading of methane. We suggest that most methane sources-most notably tropical wetlands-must have responded simultaneously to climate changes across these periods.

Vom babylonischen Exile (586) bis zum Tode des Juda Makkabi (160)

von H. Graetz

Vom babylonischen Exile (586) bis zum Tode des Juda Makkabi (160)

von H. Graetz

Right-handed neutrino production rate at T > 160 GeV

The production rate of right-handed neutrinos from a Standard Model plasma at a temperature above a hundred GeV has previously been evaluated up to NLO in Standard Model couplings (g ~ 2/3) in relativistic (M ~ πT) and non-relativistic regimes (M ≫ πT), and up to LO in an ultrarelativistic regime (M ≲ gT). The last result necessitates an all-orders resummation of the loop expansion, accounting for multiple soft scatterings of the nearly light-like particles participating in 1↔2 reactions. In this paper we suggest how the regimes can be interpolated into a result applicable for any right-handed neutrino mass and at all temperatures above 160GeV. The results can also be used for determining the lepton number washout rate in models containing right-handed neutrinos. Numerical results are given in a tabulated form permitting for their incorporation into leptogenesis codes. We note that due to effects from soft Higgs bosons there is a narrow intermediate regime around M ~g 1/2 T in which our interpolation is phenomenological and a more precise study would be welcome.

Jüdisches Familien-Buch : eine von jüdisch-religiösem Geiste getragene, belehrende u. unterhaltende Lektüre f. Schule u. Haus ; 160 Lebens- und Charakterbilder d. vorzügl. Gestalten d. jüd. Geschichte aus allen Zeitperioden u. Staaten

unter Mitw. bewährter Fachmänner hrsg. von M. Ehrentheil

Ms. hebr. oct. 160 - [Sammelband in 4 Teilen: Handschriftenkonvolut]

Vorbesitzer: Eljāqīm Carmoly; Abraham Merzbacher

Ms. Barth. 160 - Mainzer Diözesanbrevier

Vorbesitzer: Bartholomaeusstift Frankfurt am Main

Na 50 Nachlass Arthur Schopenhauer - 'Schopenhauer-Archiv', 160 - Ankündigung des Umzugs nach Thüringen

u.a.: Umzug aus gesundheitlichen Gründen nach Naumburg oder Erfurt; Einschreiten der Polizei in Frankfurt am Main; Eisenbahn Thüringen; Höhe der Miete in Berlin, Beschreibung Berliner Wohnung; Wielandt; Geheimer Hofrat Carl John;

Ms. Praed. 160 - [Sammelband in 2 Teilen: Konvolut aus Handschrift und Postinkunabel]

Vorbesitzer: Dominikanerkloster Frankfurt am Main