The Neoproterozoic Rivieradal Group of Kronprins Christian Land, eastern North Greenland

The Rivieradal Group, formally defined here, is confined to the Vandredalen thrust sheet of the Caledonian orogen in Kronprins Christian Land, eastern North Greenland. It comprises a succession of Neoproterozoic siliciclastic sediments that represent the fill of a half-graben basin. The syn-rift Rivieradal Group is overlain by post-rift sediments of the Hagen Fjord Group. The latter succession is present in both the thrust sheet and the Caledonian foreland to the west. In the foreland, where the Rivieradal Group is not represented, the Hagen Fjord Group disconformably overlies Palaeoproterozoic–Mesoproterozoic sandstones of the Independence Fjord Group

Neoproterozoic sedimentary basins with glacigenic deposits of the East Greenland Caledonides

Two major Neoproterozoic sedimentary basins that probably formed in response to an early pulse of Iapetan rifting along the Laurentian margin are well exposed in the East Greenland Caledonides. The Hekla Sund Basin is exposed at the northern termination of the East Greenland Caledonides, and it is represented by the Rivieradal and Hagen Fjord Groups, which attain a cumulative thickness of 8-11 km. The evolution of this basin reflects deposition during active rifting and a postrift thermal equilibration stage. The Eleonore Bay Basin of East Greenland includes the deposits of the Eleonore Bay Supergroup of early Neoproterozoic age overlain by Cryogenian (mid-Neoproterozoic) glacial deposits of the Tillite Group, which have a combined thickness in excess of 14 km. Four stages of basin evolution may be distinguished based on paleogeographic reorganizations of the shelf and a change from siliciclastic to carbonate deposition, and the final stage was dominated by glacigenic deposition. Major regional stratigraphic breaks seem to be absent, as is other evidence of riftrelated sedimentation, suggesting deposition in one or a series of connected ensialic basins. A comparison with other Neoproterozoic basins along the Laurentian margin of the Iapetus Ocean shows similarities between the Eleonore Bay Basin and coeval deposits on Svalbard and the Central Highlands of Scotland. The development of an extensive carbonate platform during the later stages of both the Eleonore Bay and Hekla Sund Basins testifies to a period of tectonic stability prior to onset of Iapetus rifting. The extent of this carbonate platform may have been even larger, since similar successions are present in the Caledonides of Scotland and Ireland. © 2008 The Geological Society of America

East Greenland Caledonides: stratigraphy, structure and geochronology: The Neoproterozoic Rivieradal Group of Kronprins Christian Land, eastern North Greenland

The Rivieradal Group, formally defined here, is confined to the Vandredalen thrust sheet of the Caledonian orogen in Kronprins Christian Land, eastern North Greenland. It comprises a successionof Neoproterozoic siliciclastic sediments that represent the fill of a half-graben basin. The syn-rift Rivieradal Group is overlain by post-rift sediments of the Hagen Fjord Group. The latter succession is present in both the thrust sheet and the Caledonian foreland to the west. In the foreland, where the Rivieradal Group is not represented, the Hagen Fjord Group disconformably overlies Palaeoproterozoic–Mesoproterozoic sandstones of the IndependenceFjord Group

The consequences of being in an infectious biofilm: Microenvironmental conditions governing antibiotic tolerance

© 2017 by the authors. Licensee MDPI, Basel, Switzerland. The main driver behind biofilm research is the desire to understand the mechanisms governing the antibiotic tolerance of biofilm-growing bacteria found in chronic bacterial infections. Rather than genetic traits, several physical and chemical traits of the biofilm have been shown to be attributable to antibiotic tolerance. During infection, bacteria in biofilms exhibit slow growth and a low metabolic state due to O2 limitation imposed by intense O2 consumption of polymorphonuclear leukocytes or metabolically active bacteria in the biofilm periphery. Due to variable O2 availability throughout the infection, pathogen growth can involve aerobic, microaerobic and anaerobic metabolism. This has serious implications for the antibiotic treatment of infections (e.g., in chronic wounds or in the chronic lung infection of cystic fibrosis patients), as antibiotics are usually optimized for aerobic, fast-growing bacteria. This review summarizes knowledge about the links between the microenvironment of biofilms in chronic infections and their tolerance against antibiotics