recorded parvus Isarcicella isarcica conodont recorded parvus Isarcicella isarcica conodont in to zones (earliest Triassic). Sea surface temperatures (SST) reconstructed from oxygen isotopes of conodont apatite increase by 8 - 10 °C over an ∼ C. iranica C. extrapolated time interval of 39 ka with the onset of global warming occurring in the ( meishanensis ) Zone of the latest Permian. Climate warming documented in the Armenian sections is comparable to published time-equivalent shifts in SST in Iran and South China suggesting that this temperature change represents a true global signature. By correlating the Armenian and Iranian section with the radiometrically well-dated Meishan GSSP (Global Stratotype Section and Point) section (South China), the 13 negative shift in δ C is estimated to have occurred 12 - 128 ka prior to the onset of global warming. This temporal offset is unexpected given the synchrony in changes in atmospheric CO and global temperature as 2 13 seen in Pleistocene ice core records. The negative δ C excursion is explained by the addition of emission of isotopically light CO and CH from thermogenic heating of organic carbon-rich sediments by Siberian Trap sill 2 4 13 18 intrusions. However, the observed time lag in the δ C and δ Oshifts questions the generally assumed cause- effect relationship between emission of thermogenically produced greenhouse gases and global warming. The onset of temperature rise coincides with a significant enrichment in Hg/TOC (total organic carbon) ratios arguing for a major volcanic event at the base of the extinction interval. Whether global warming was a major factor for the Late Permian mass extinction depends on the duration of the extinction interval. Warming only starts at the base of the extinction interval, but with the extinction encompassing a time interval of 60 ± 48 ka, global climate warming in conjunction with temperature-related stressors as hypoxia and reduced nutrient availability may have been one of the major triggers of the most devastating biotic crisis in Earth history.

Johannessen, S.C., Greer, C.W., Hannah, C.G., King, T.L., Lee, K., Pawlowicz, R., Wright, C.A., 2020. Fate of diluted bitumen spilled in the coastal waters of British Columbia, Canada. Marine Pollution Bulletin 150, 110691.

http://www.sciencedirect.com/science/article/pii/S0025326X19308471 There is public concern about the behaviour of spilled diluted bitumen (dilbit) in marine and estuarine waters. We provide a preliminary assessment of the results of laboratory experiments and models, in the context of environmental conditions in the coastal waters of British Columbia. Most dilbit spilled within this region would likely float at the surface and be transported to shore by winds and currents. Fresh dilbit is too light to sink in coastal waters. Highly weathered dilbit could sink where salinity is less than 14, typically only near river mouths and in the top 1 -3 mof fjords after heavy rainfall. Subsurface plumes of weathered dilbit could re - emerge at the surface. Sinking oil-particle aggregates are unlikely to form in coastal waters. However, dilbit could be entrained below the surface by wave mixing during storms and to depths of 150 mby coherent mixing in the Haro Strait tidal convergence zone.

Johnsen, U., Sutter, J.-M., Reinhardt, A., Pickl, A., Wang, R., Xiang, H., Schönheit, P., 2020. D-Ribose catabolism Haloarcula in archaea: Discovery of a novel oxidative pathway in species. Journal of Bacteriology 202, e00608-19.

http://jb.asm.org/content/202/3/e00608-19.abstract Abstract: The Haloarcula species H. marismortui and H. hispanica were found to grow on d-ribose, d-xylose, and l-arabinose. Here, we report the discovery of a novel promiscuous oxidative pathway of pentose degradation based on genome analysis, identification and characterization of enzymes, transcriptional analysis, Haloarcula and growth experiments with knockout mutants. Together, the data indicate that in spp., d-ribose, d- xylose, and l- arabinose were degraded to α -ketoglutarate involving the following enzymes: (i) a promiscuous pentose dehydrogenase that catalyzed the oxidation of d-ribose, d-xylose, and l-arabinose; (ii) a promiscuous pentonolactonase that was involved in the hydrolysis of ribonolactone, xylonolactone, and arabinolactone; (iii) a highly specific dehydratase, ribonate dehydratase, which catalyzed the dehydration of ribonate, and a second enzyme, a promiscuous xylonate/gluconate dehydratase, which was involved in the conversion of xylonate, arabinonate, and gluconate. Phylogenetic analysis indicated that the highly specific ribonate dehydratase constitutes a novel sugar acid dehydratase family within the enolase superfamily; and (iv) finally, 2-keto-3- deoxypentanonate dehydratase and α -ketoglutarate semialdehyde dehydrogenase catalyzed the conversion of 2- keto-3- deoxypentanonate to α - ketoglutarate via α -ketoglutarate semialdehyde. We conclude that the expanded